The_Gerry-Mander_Edit.pngRedistricting encourages manipulation of our elections by allowing incumbent politicians to help partisan allies, hurt political enemies and choose their voters before the voters choose them. The current process is used as a means to further political goals by drawing boundaries to protect incumbents and reduce competition, rather than to ensure equal voting power and fair representation.

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The Many Ways to Re-Draw Districts

Many ways exist for electing congressional delegations and state legislatures, but every state currently does so by dividing the state into legislative districts that must be redrawn every decade after a new census. Because states create districts, they must decide how district lines will be drawn.

In many states, the state legislature draws the districts and openly does so in order to influence the likely partisan makeup of the legislature, discourage electoral competition and/or generally hurt their political enemies and help their friends. However, goals like those fly in the face of democratic values like fair representation of voters and the ability of voters to influence election results.

Who Draws Congressional Districts?  

infogram_0_congressional_drawingCongressional Redistricting//

Who Draws District Lines in State Legislatures?


infogram_0_state_districts-4redistricting State districts//


Redistricting Reforms

Redistricting reforms attempt to address the legislative tendency to undermine electoral accountability through districting. Possible redistricting reforms include: 

  • Criteria-Driven Civil Servant Approach: Based on the approach taken in Iowa, this reform would have district maps drawn by a nonpartisan body of civil servants according to criteria set by statute. In Iowa, the legislature must then vote to adopt the maps without amendment (which they routinely do), with the same body redrawing the maps if the legislature votes the first ones down.

  • Criteria-Driven Independent Commission Approach: Based on the approach taken in California, this reform would have district maps drawn by a commission selected in a manner to maximize citizen participation and independence from legislative pressure. That body would then draw those maps based on criteria set by statute.

  • Criteria-Driven Legislative Redistricting with Judicial Approval: Based on the approach taken in Florida, this reform would continue to allow the state legislature to adopt district maps, but it would require it to do so according to criteria set by statute. At the end of the process, the maps would have to be approved by the state Supreme Court as complying with the criteria.

  • Bipartisan Commission: Based on the approach taken in New Jersey, this reform would have district maps drawn by a bipartisan commission with a public interest tiebreaker. That commission would then draw districts according to criteria set by statute. The general goal is to have both  parties reach a compromise in generating a plan, which has earned this approach support from the Bipartisan Policy Center.

  • Legislative Redistricting with Public Input and Transparency: This reform would allow the state legislature to adopt district maps. However, it would include two changes modeled on parts of Idaho’s independent commission process: first, it would allow the public to submit plans and make those plans available to the public; and second, it would require that all meetings, hearings, and so on concerning redistricting be open to the public.

Where an approach relies on criteria describing districting priorities, the most common criteria used include:

  • Contiguity
  • Consistency with natural and political boundaries (county lines, for example)
  • Compactness (low perimeter to area ratio or a similar measure)

Sometimes competitiveness is included as well, with the goal of creating districts that will be as evenly split in two-party partisanship as possible. Competitiveness is a controversial criterion, both because it can undermine the representation of minorities and because it requires those drawing the lines to actively consider the impact of the districts on electoral outcomes. Often, those drawing the lines are explicitly forbidden from considering partisanship data, like voter registration levels or voting histories, or incumbents’ places of residence.


Summary of Literature on Redistricting Reform

Many hours and reams of paper have been dedicated to identifying the impact of different redistricting reforms on competition, incumbency, turnout and other desirable outcomes.  Unfortunately, the literature generally indicates that redistricting reforms, including independent redistricting commissions, have only small impacts on electoral outcomes. States with independent redistrict commissions remain beleaguered by noncompetitive congressional elections, high incumbency re-election rates, and low voter turnout.  

Below is an annotated literature review for further study. 

Further Reading

  • Carson, Jamie L., and Michael H. Crespin. "The effect of state redistricting methods on electoral competition in United States House of Representatives races." State Politics & Policy Quarterly 4, no. 4 (2004): 455-469. Online. Carson and Crespin explore whether the method by which states draw legislative districts affect partisan competition in the elections that are held in those districts.  They find that more competitive elections occur when courts and commissions are directly involved in the redistricting process, as opposed to when redistricting is handled only in the state legislative process.

  • Cottrill, James B. "The effects of non-legislative approaches to redistricting on competition in congressional elections." Polity 44, no. 1 (2012): 32-50. Online. Cottrill studies instances in which redistricting approached changed for congressional elections between 1982–2008. His research suggests that non-legislative redistricting did not reduce the typical margins of incumbents’ victories, nor did they increase the likelihood that incumbents would lose. Cottrill concludes that the data raise questions about the common contention that non-legislative approaches will promote turnover of elected officials.

  • Gelman, Andrew and Gary King.  1994. "Enhancing Democracy Through Legislative Redistricting" American Political Science Review. 88(3):541-59. Online. Gelman and King argue that the legislative redistricting (including partisan gerrymandering) is not nearly as problematic for American representative democracy as often presumed. They argue that legislative redistricting increases responsiveness. Further, they argue that all electoral systems that involve districting produce partisan bias. 

  • Jacobson, Gary C. 2006. “Why Other Sources of Polarization Matter More” in Red and Blue Nation?, Vol. 1, eds. Pietro S. Nivola and David W. Brady. Washington, DC: Brookings Institution Press: 284-290. Online. Discusses approvingly Thomas Mann’s argument that redistricting has played only a small part in the polarization of the house. Rather, Jacobson argues, polarization has resulted from changing behavior of voters and their spatial distribution.

  • Kousser, Thad, Justin H. Phillips, and Boris Shor. 2013. “Reform and Representation: Assessing California’s Top-Two Primary and Redistricting Commission.” Presented at the 2013 Annual Meeting of the American Political Science Association, Chicago. Online. The authors explore whether electoral reforms can create conditions that lead to better legislative representation. Using the congruence between a legislator’s ideological position and the average position of his/her district’s voters as their central measure, they show that, immediately after the introduction of Top-Two and an independent citizens redistricting commission, state legislators were no more congruent with the districts than before, and indeed may have strayed further from their district’s average voter.  

  • Krebs, Timothy and Jonathan Winburn. 2011  "State and Local Elections: The Unique Character of Sub-National Contests." In S. Medvic (eds).  New Directions in Campaigns and Elections Routledge. The authors compare competitiveness across different types of redistricting systems.

  • Lindgren, Eric, and Priscilla Southwell. "The Effect of Redistricting Commissions on Electoral Competitiveness in US House Elections, 2002-2010." Journal of Politics and Law 6, no. 2 (2013): p13. Online. Lindgren and Southwell examine electoral districting in the post-2000 Census years to determine the variation in competitiveness for subsequent elections to the U.S. House of Representatives. The authors find that independent commissions resulted in more competitive districts.
  • Litton, Noah. "Road to Better Redistricting: Empirical Analysis and State-Based Reforms to Counter Partisan Gerrymandering" Ohio St. LJ 73 (2012): 839. Online.  Litton argues that combining a nonpartisan redistricting commission, a citizen redistricting competition, and limited legislative oversight and approval of the final congressional map would achieve what no other redistricting reform purports to accomplish: removing political avarice from an inherently and irreconcilably political process. In the process, Litton describes the Iowa approach to redistricting (p. 856) and compares the use of the Iowa civil servant approach against Ohio’s partisan and Pennsylvania’s bipartisan approaches, finding that Iowa experienced the highest levels of responsiveness and the near elimination of partisan bias in its state legislative results in 1990-2010.  
  • Mann, Thomas E. 2006. “Polarizing the House of Representatives: How Much Does Gerrymandering Matter?” in Red and Blue Nation?, Vol. 1, eds. Pietro S. Nivola and David W. Brady. Washington, DC: Brookings Institution Press: 263-283. Mann argues that redistricting is a much smaller contributor to congressional polarization than often thought, with the spatial distribution of voters being a greater contributor. 

  • Masket, Seth E., Jonathan Winburn, and Gerald C. Wright. "The gerrymanderers are coming! Legislative redistricting won't affect competition or polarization much, no matter who does it." PS: Political Science & Politics 45, no. 01 (2012): 39-43. Online. The authors analyze whether partisan redistricting is responsible for declining electoral competition and increasing legislative polarization. Their analysis of evidence from state legislatures during the last decade suggests that the effects of partisan redistricting on competition and polarization are small, considerably more nuanced than reformers would suggest, and overwhelmed by other aspects of the political environment
  • McCarty, Nolan, Keith T. Poole, and Howard Rosenthal. 2009. “Does Gerrymandering Cause Polarization?” American Journal of Political Science 53(7): 666-680. Online. The authors test the whether partisan gerrymandering causes polarization in Congress. Using simulations of various “neutral” districting procedures, they find that the actual levels of congressional polarization are not much higher than those produced by the simulations. 

  • McDonald, Michael P. "Regulating redistricting." PS: Political Science & Politics 40, No. 04 (2007): 675-679. Online. McDonald writes about the redistricting processes observing that legislators, party leaders, staff, consultants, and lawyers spend considerable time, effort, and money on their obsession with district boundaries, while political scientists come to mixed conclusions about the impact of redistricting on electoral politics. 

  • McGhee, Eric and Vlad Kogan. “Redistricting California: An Evaluation of the Citizens Commission Final plans”. California Journal of Politics and Policy 4 no 1 (2012): 1-32. In their study, McGhee and Kogan assess the success of California’s Citizen Redistricting Commission by comparing the legislatures elected under the new districts to those elected under the old legislatively drawn districts. Overall, they find that the non-partisan commission with citizen input created districts that were modestly more competitive and favored Democrats less than previously thought. The new districts also kept communities better together than previous maps, created more compact districts, and districts that had a better chance of minority representation (p. 25). 

  • Oedel, David G., Allen K. Lynch, Sean E. Mulholland, and Neil T. Edwards. "Does the Introduction of Independent Redistricting Reduce Congressional Partisanship." Vill. L. Rev. 54 (2009): 57. Online. The authors analyze partisan voting patterns from members of congress elected in districts drawn by different means. Then, using regression analysis, they find a significant correlation between partisan voting patterns and independence of the redistricting process. They conclude that independent redistricting likely reduces partisanship and that politicized redistricting may exacerbate partisanship. 

  • Stephanopoulos, Nicholas. “Our Electoral Exceptionalism”. University of Chicago Law Review 79 (2013): 1-68. Online.  In his article, Stephanopoulos compares the redistricting approach of the United States to other countries. He finds that the US’s approach to drawing districts through elected institutions rather than independent commissions, of diversifying districts rather than keeping communities together, and use of implicit instead of explicit mechanisms to encourage minority representation makes the US an outlier amongst democratic nations. Furthermore, the US’s outlier actions result in partisan bias, poor election turnout, and low confidence in representative branches. Stephanopoulos recommends the US undertake several reforms to improve its districts, including use of a non-elected, political agencies to draw district maps-similar to Iowa’s civil servant approach.  

  • Stephanopoulos, Nicholas. “Communities and the California Commission”. Stanford Policy and Law Review 23 no 2 (2012): 281-334. Online. Using a newly developed technique for measuring “communities of interest”, Stephanopoulos determines that California’s Citizen Commission created new districts with lower levels of spatial diversity (i.e.-districts have more community homogeneity) than other areas of the country. The result is distinct communities with chances of better aligned representation. 

  • Tolbert, Caroline J., Daniel A. Smith, and John C. Green. "Strategic Voting and Legislative Redistricting Reform District and Statewide Representational Winners and Losers." Political Research Quarterly 62, no. 1 (2009): 92-109. Online. Tolbert et al use survey data to explore mass support in the American states for changing how legislative districts are drawn. They find evidence that representational losers at statewide and district levels are more likely to vote for reforms to create nonpartisan redistricting when they appear on the ballot, while electoral winners oppose reform.

Cover Page of Redistricting Reform in the South Report

Redistricting Reform in the South

Nowhere in the United States are the pernicious effects of gerrymandering and winner-take-all, single-member districts more clearly visible than in the South. In the line of states running from Louisiana to Virginia, congressional races are nearly universally uncompetitive, Democrats are systematically disadvantaged, and African Americans are underrepresented in spite of the Voting Rights Act.

Download: Redistricting Reform in the South

Consider these statistics from FairVote's Monopoly Politics 2014 section on the effect of winner-take-all in the South over the last two decades:

  • Percentage of the 133 U.S. House seats held by each party in 1991 in the South (defined as the 14 states south of and including Texas, Oklahoma, Arkansas, Kentucky, West Virginia and Virginia): 67% Democratic (89 seats) to 33% Republican (44 seats).
  • Percentage of the 152 House seats for each party in those states today: 28% Democratic (42 seats) to 72% (110 seat) Republican.
  • Number of Democrats by race in the 133 U.S. House districts in the South in 1991: 81 white, 4 African American, 4 Latino.
  • Number of Democrats by race in the 152 U.S. House districts from the region today: 18 white, 18 African American, 6 Latino

This report examines different options for how redistricting in the South could be reformed through the creation of sample maps. These maps illustrate the fundamental trade-offs inherent in different reform options – especially those options that continue to use the single-member, winner-take-all district system.

While the maps presented in this report are not the only maps that could be created under the criteria for each reform option, they represent our best effort at following the dictates of those criteria. The maps are not intended to predict exactly what would happen if different reforms were enacted, but rather to give a general idea of how effective those reforms would be at achieving their goals.

The states studied in this report are those in the belt of states from Louisiana up through Virginia, along with Tennessee. More specifically, they are: Louisiana, Alabama, Mississippi, Georgia, South Carolina, Tennessee, North Carolina, and Virginia.

The redistricting reforms considered have all been put forward as solutions to either the Republican bias of current district maps, the lack of competition in those districts, the lack of compactness in those districts, or the insufficient representation of racial minorities:

  • Eliminating the Voting Rights Act such that Democratic voters are not overly concentrated in just a few majority-minority districts
  • Establishing independent redistricting commissions to draw neater, more compact district lines
  • Establishing independent redistricting commissions with the explicit criteria of drawing districts that will accurately represent the two parties’ statewide vote shares and create competition
  • Enacting fair representation voting by requiring an independent redistricting commission to draw multi-member districts that would use ranked choice voting, to the end of ensuring partisan fairness, creating competition in every district, and enhancing the representation of racial minorities

FairVote has a clear preference among these reforms: fair representation voting. As the results of this report show, fair representation voting plans are much more likely to accomplish partisan fairness, competition, clean district lines, and racial representation than other reforms without necessitating trade-offs among those goals. They do so by giving far more voters an opportunity to elect preferred candidates.

Download: Redistricting Reform in the South

Reforms to Enhance Independent Redistricting Proposals

Several states have attempted to make their redistricting processes fairer by instituting independent redistricting commissions that take direct control of redistricting away from the state legislature. While this is a worthwhile reform strategy to address the conflict of interest inherent in politicians picking their own voters, independent redistricting alone cannot guarantee competitive elections, partisan fairness, racial fairness, geographic coherence and accountable leadership at the same time. Independent redistricting speaks to how district lines are drawn, but it does not change the more important factor of what election method is used to cast and count votes in those districts. 

Competition, for example, requires districts with a narrow partisan division, which almost certainly means that racial minorities will not have the power to consistently elect candidates of choice as can be required under the Voting Rights Act. Competitive districts also mean that overall partisan balance can swing wildly based on a small shift in votes statewide. And given that most areas have natural partisan leanings, drawing competitive districts makes it difficult to follow traditional criteria like compactness and maintenance of local political lines.

Perhaps due to these inherent conflicts, independent redistricting has had low impact on electoral competition, and a mixed impact on fair partisan and racial representation. We need voting system reforms to enhance redistricting reform.

Download the full report

Model State Redistricting Reform Criteria

The sample statutory language below indicates one vision of a potential redistricting reform proposal that would preserve the independent redistricting process, without precluding the use of multi-winner districts with proportional voting. The proposal below also prioritizes competitiveness and legislative diversity as goals for representation.


1.    “Proportional voting system” means any voting system that ensures the election of any candidate in a multi-member district who receives a share of votes cast that is at least one vote greater than one-third of the total number of votes cast in the district.

2.    “Commission” means the independent legislative redistricting commission pursuant to this chapter.

3.    “Ideal district population” is determined by dividing the number of districts to be established into the population of the state reported in the latest federal decennial census.

4.    “Multi-member district” means any legislative district that elects more than one legislator.

5.    “Partisan public office” means: (1) an elective or appointive office in the executive or legislative branch or in an independent establishment of the federal government; (2) an elective office in the executive or legislative branch of the government of this state, or an office of the government of this state which is filled by appointment of executive or legislative authority; (3) an office of a county, municipality, or other political subdivision of this state which is filled by an election process involving the nomination and election of candidates on a partisan basis.

6.    “Plan” means a plan for legislative reapportionment drawn up pursuant to the requirements of this chapter.

7.    “Political party office” means an elective office in the national or state organization of a party.


1.    Not later than February 15 of each year ending in one, a redistricting commission shall be established as provided in this section. The commission’s only functions shall be those described in Section III.

2.    The commission shall be the only means of redrawing Congressional, state assembly and state Senate district lines.

3.    The commission shall only be convened in a year not ending in 1 subject to a court order.

4.    The commission shall be convened pursuant only to either Sec. IV or Sec. V of this article.


1.    The commission shall develop a plan for the apportionment of Congressional representatives and state [house/assembly] and senatorial districts based on the most recent decennial census. The commission shall forward the plan to the speaker of the house of representatives and the president of the senate, and shall include legislation necessary to effectuate the plan.

2.    The commission shall decide whether to draw single member districts, multi-member districts with proportional voting systems, or some combination thereof.

3.    If the commission cannot decide on whether to draw single member districts, multi-member districts with proportional voting systems, or some combination thereof, it is empowered to empanel a Citizens’ Assembly to study the issue and make a recommendation to the commission.


1.    As soon as possible after January 1 of each year ending in one, the legislative service bureau shall obtain from the United States bureau of the census the population data needed for legislative districting which the census bureau is required to provide this state under United States Pub. L. 94-171, and shall use that data to assign a population figure based upon certified federal census data to each geographic or political unit.

2.    Not later than April 1 of each year ending in one, the legislative service bureau shall deliver to the secretary of the senate and the chief clerk of the house of representatives identical bills embodying a plan of legislative and congressional districting prepared in accordance with section IV.


1.    The commission shall be composed of nine members and shall reflect the diversity of the state.

2.    Prior to December 31 in a year ending in zero, the Supreme Court shall establish a pool of 36 potential commission members. A person is eligible to be a member of the commission if the person:

a.    Is a retired state judge or a federal judge who has served in a federal court in this state and has retired or taken senior status;

b.    Has never held a partisan public office; and

c.    Has not changed the person's political party affiliation indicated in the person's voter registration records during the five years immediately preceding appointment.

3.    One third of the pool shall be registered members of the largest political party in the state, one third of the pool shall be registered members of the second largest political party in the state, and one third of the pool shall not be registered members of either of the two largest political parties in the state.

4.    A random drawing shall be held in the following manner to determine which members of the pool shall serve on the commission.

a.    Three members will be chosen by lot from those members of the pool who are registered members of the largest political party in the state.

b.    Three members will be chosen by lot from those members of the pool who are registered members of the second largest political party in the state.

c.    Three members will be chosen by lot from those members of the pool who are not registered members of either of the two largest political parties in the state.

5.    A person appointed to the commission under this subsection, before commencing service on the commission, shall pledge in writing that during the person's service as a member of the commission and for at least five years after the date the person's service as a member of the commission is concluded the person will not seek, accept or hold:

a.    A public office;

b.    The position of an officer of a political party; or

c.    The position of a compensated lobbyist.

6.    The terms of office of members of the commission expire upon the last filing of a redistricting plan under this section or upon discharge of the members by the Supreme Court under paragraph (a) of subsection (10) of this section.

7.    The Supreme Court shall identify qualified persons willing to serve as members of the commission. From the list of qualified persons, the court shall appoint at random four persons to serve as members of the commission. If the court appoints a panel in which more than two members are registered to vote as members of one of the two largest political parties in this state, then the court shall excuse one member of the panel by lot and randomly appoint and excuse new members until a panel is appointed consisting of two members belonging to each of the two largest political parties in this state.

8.    The four members of the commission appointed by the Supreme Court under paragraph (a) of this subsection shall identify qualified persons willing to serve as the fifth member of the commission. From the list of qualified persons, the four members shall appoint the fifth member by an affirmative vote of three-fourths of the members.


1.    Districts shall be drawn in compliance with the United States Constitution and the federal Voting Rights Act (42 U.S.C. §1973 et seq).

a.    The commission may create plans containing multi-member districts with a proportional voting system, single member districts, or a combination thereof. Each such district shall have a population per representative as nearly equal as practicable.

2.    To the greatest extent possible, the commission shall maximize both representativeness and, where practicable, competitiveness, though neither goal shall be superior to the other.

a.    A representative plan is one where racial groups and other communities of interest are able to elect representatives in proportion to their percentage of the voting age population.

b.    If it is impracticable to draw competitive districts in the state, the commission shall not use party registration information.

3.    The commission shall hold at least three public hearings throughout the state for receiving and considering proposed redistricting plans and public comment from any member of the Legislative Assembly or the public.

4.    In no circumstance shall the commission know or take into account the address of any individual, including an officeholder.

5.    Information concerning party registration and historical election returns shall only be used once a plan has been drawn, and shall only be used to test the plan for compliance with the stated goals of this article.

6.    Each district shall be as contiguous as compact as practicable. With respect to compactness, to the extent practicable a contiguous area of population shall not be bypassed to incorporate an area of population more distant.

a.    Respect for contiguous and compact districts shall be secondary to the goals of representativness and competitiveness.

7.    District boundaries shall conform to the existing geographic boundaries of a county, city, or city and county, and shall preserve identifiable communities of interest to the greatest extent possible. A redistricting plan shall provide for the most whole counties and the fewest county fragments possible, and the most whole cities and fewest city fragments possible. For the purposes of this section, communities of interest are defined by similarities in social, cultural, ethnic, and economic interest, school districts, and other formal relationships between municipalities.


1.    The commission shall forward the plan to the legislature before April 1 of each year ending in one. The House of Representatives and the Senate shall vote on the plan expeditiously, but not less than 7 days after the plan is received and made available to the members of both houses. The plan shall be voted on using a procedure allowing no amendments, other than those of a purely corrective nature.

2.    If the plan fails to be approved by a constitutional majority in either the House of Representatives or the Senate, the clerk of the House of Representatives or the Senate, as the case may be, shall at once transmit to the commission reasons why the plan was not approved. The commission shall then prepare a second plan in accordance with Section IV, and taking into account the reasons cited by the House of Representatives or senate for its failure to approve the plan insofar as it is possible to do so within the requirements of Section IV. The second plan shall be delivered to the speaker of the house of representatives and the president of the senate not later than May 1 of the year ending in one, or 21 days after the date of the vote by which the house of representatives or the senate fails to approve the plan submitted under paragraph I, whichever date is later. It is the intent of this chapter that, if a second plan is necessary, it shall be brought to a vote not less than 7 days after the plan is made available to the members of the general court, in the same manner as prescribed for the plan under paragraph I.


1.    Any elector may bring an action directly to the [highest court in the state] alleging that a law establishing or changing boundaries of any Senate, [Assembly/House], or congressional district does not comply with the requirements of this article. An action filed with the Supreme Court pursuant to this section must be filed within 30 days of the enactment of the challenged law. The Supreme Court shall render a decision within 60 days after the filing of a petition and the Court's failure to do so shall constitute a denial of the petition. If the Supreme Court finds a redistricting plan to be in violation of this article, it shall order that a new plan be adopted pursuant to this article.


1.    If any section, part, clause, or phrase of this article is for any reason held to be invalid or unconstitutional, the remainder shall not be affected, but shall remain in full force and effect.


We recommend the following excellent web resources to learn more about redistricting.

Justin Levitt’s “All About Redistricting

Justin Levitt, Professor of Law at Loyola Law School Los Angeles, has created a comprehensive, state-by-state guide to redistricting with excellent content and coverage. The easily-navigated website provides a page for each state outlining the current status of redistricting, state procedures, pending litigation, and current partisan breakdown of each state legislature. “All About Redistricting” also provides links to numerous other resources including data tools, overview guides, information on the redistricting process, academic articles, and reform advocacy groups. This site is perhaps the most comprehensive resource on the web for those seeking accessible, updated, and detailed redistricting information. 

Ballotpedia: State-by-State Redistricting Procedures

Ballotpedia provides coverage of redistricting developments from across the country. Each state has a comprehensive page detailing state procedures, census data, district maps, bill updates, citizen involvement, and lawsuit outcomes. 


RedistrictingOnline provides information regarding redistricting law, process, news, and scholarly commentary. The site also provides both daily and weekly news links from across the nation, as well as a “Commission Tracker” which provides updates on the progress of such groups. RedistrictingOnline also includes a page tracking current litigation with links to actual court documents.  

Brennan Center for Justice

The Brennan Center provides many redistricting resources including a blog, summaries of court cases, legal and political analysis, and press releases. The organization also publishes a comprehensive report, A Citizen’s Guide to Redistricting, which has been updated for 2010 and is accessible online. Particularly useful is the “Redistricting 101” page that provides an issue-by-issue look at the importance of redistricting, problems with the current system, and steps citizens can take to address such deficiencies. 

National Conference of State Legislatures 

NCSL is a bipartisan organization that serves legislators and staff throughout the country. The information provided on their redistricting site includes seminar presentations for states, the current status of redistricting law, and federal issues. Particularly useful is the redistricting glossary which provides understandable definitions of important terms. 

Public Mapping Project

The Public Mapping Project provides software that allows the public to create redistricting plans.  The purpose is to develop increased transparency and public participation in the redistricting process. The site is mostly used to deploy the software, but it also contains a number of links to redistricting resources and news from around the country. The “Congressional Redistricting Forecast” section provides a national overview of the process, as well as a state-by-state guide to redistricting.

Other Resources

The following resources provide additional information about state redistricting processes, redistricting litigation, and other matters related to reapportionment and redistricting reform.


Redistricting has an impact on every American voter, but is often an opaque process with an insiders' vocabulary that can be a source of confusion for people who are unfamiliar with redistricting language. Using pre-existing sources like the Texas Legislative Council, NCSL, Redistricting the Nation and Louisiana's Redistricting, along with our own analysis, here is a guide to key terms frequently used within the redistricting community.

Alternative Population Base: Population count other than the official census data that is used for redistricting.  One example of an alternative population base is "voting age population."

Alternative voting system: See "proportional voting"

American Community Survey (ACS): Ongoing census survey sent to a sample of three million housing units annually. The ACS collects detailed demographic and socioeconomic population and housing characteristics, similar to the information collected on the former long form census questionnaire. The data is collected continuously rather than once a decade, so the ACS provides more current data.

Area dispersion: Measurement comparing the relative degree to which a district's area is compact with the area of a similar compact figure. It is the ratio of the area of the district to the area of the smallest convex polygon that can enclose the district. [See "compactness".]

Assignment unit: Unit of geography that may be used as a building block to draw a redistricting plan.  

Bailout:  The power jurisdictions covered by Section Five of the Voting Rights Act have to seek their permanent removal from preclearance requirements.

Candidate of choice: The candidate favored by  a like-minded group of racial minority voters in a district. The Voting Rights Act requires that certain minority groups be given enough numbers in a district so that the minority group has the ability to elect their own candidate of choice without being continually outvoted by racial/ethnic majorities.

Census: Process of surveying and counting the U.S. population, using mailed surveys and in-person visits to homes, mandated by the U.S. Constitution and done every ten years by the federal government. Its results are used for reapportioning House seats among the states and redistricting districts within states. The last Census took place in 2010.

Census block: Smallest unit of census geography for which population data are counted and reported. Census blocks are delineated by the Census Bureau and are generally bounded by physical features such as roads, creeks, or shorelines, but also may be bounded by invisible features such as city, county, school district, or voting precinct boundaries. Census blocks are generally between 30,000ft² and 40,000ft².

Census block group: Subdivision of a census tract composed of a group of contiguous census blocks.

Census Bureau: Government agency that is responsible for the United States Census. It also gathers other national demographic and economic data. As part of the United States Department of Commerce, the Census Bureau serves as a leading source of data about America's people and economy.

Census Designated Place (CDP): Densely settled, unincorporated area locally identified by a name, such as an unincorporated town, for which the Census Bureau reports population. The boundaries of a census designated place are established by the Census Bureau in cooperation with state and local government officials.

Census tract: Set of block groups combined to create a unit of census geography delineated by local committees in accordance with census bureau guidelines for the purpose of collecting and presenting decennial census data.

Choice voting: A form of proportional representation (PR) that is used in some American elections and is widely used for local and some national elections in democracies such as Australia, Ireland, Malta and United Kingdom. Under choice voting, like-minded representatives win seats in multi-seat districts in proportion to their share of voting support. Choice voting also assures that political parties or candidates will gain the percentage of legislative seats that reflects their public support.  Choice voting is also called "single transferable vote'' and "preference voting."

Citizen Voting Age Population CVAP: Number of persons in a geographic unit who are citizens and at least 18 years of age.

Community of interest (COI): Group of people in a geographical area, such as a specific region or neighborhood, who have common political, social, or economic interests. Examples of COI's are groups who are committed to preserving a local park, creating a new subway line in a city or achieving increased funding for a community college.

Compactness: Minimizing the distance between all parts of a district.  There are many types of compactness measures including: area dispersion and perimeter.

Contiguity: A district that is within one continuous boundary and whose parts all touch one another at more than a point. All districts in the United States must be contiguous, however, some districts stretch the limits of this requirement by connecting different landmasses through water or having two districts intersect at a single point that takes up no area.

County lines: The boundary between counties within a state.  Splitting counties between districts is prohibited in certain states when it is possible to keep them intact.

Cracking: Splitting a like-minded voting group's electoral strength by dividing its population into multiple districts.

Cumulative voting: A semi-proportional voting system used in about seventy American jurisdictions in which voters cast as many votes as there are seats. But unlike winner-take-all systems, voters are not limited to giving only one vote to a candidate. Instead, they can put multiple votes on one or more candidates. For instance, in an election for a five-seat body, voters could choose to give one vote each to five candidates, two votes to one candidate and three to another, or all five votes to a single candidate. If members of a minority group work together and get behind a single candidate, "plumping" all of their votes on him or her, they can hope to elect that candidate, even if they only make up a minority share of the population.

Department of Justice (DOJ): Department within the federal government's executive branch which ensures that federal law is followed and prosecutes offenders when it is not.  The DOJ has a Voting Section that monitors state election law and enforces the Voting Rights Act.

Deviation: Amount or percentage by which a district's population varies from that district's ideal population.

Dilution: Reduction in the voting strength of a particular group resulting from redistricting and use of winner-take-all elections. The phrase "minority vote dilution" describes racial minorities being in a position of not being able to elect candidates of choice.

District: Boundaries that define the constituency of an elected official. A district can include one or more elected legislators.

Fourteenth Amendment to the U.S. Constitution: Provision of the U.S. Constitution that includes the Equal Protection Clause, which prohibits the states from denying persons equal protection of the law. The Equal Protection Clause is the primary basis of the one-person, one-vote principle, which courts in redistricting cases have defined to mean equality of population (including non-eligible voters) in districts.

Fifteenth Amendment to the U.S. Constitution: Provision of the U.S. Constitution that prohibits the right to vote from being denied or abridged on account of race.

Gerrymander: Drawing a district with boundaries that favor one or more groups of voters and/or some candidates over others.

  • Partisan gerrymandering: Drawing a district to favor one political party over others.
  • Racial gerrymandering: Drawing a district to favor one racial group over others.

Ideal district population: Number of people that should be in each of a jurisdiction's districts. This number is calculated by dividing the total population of the jurisdiction by the number of districts being created.  The number can vary if other measures are used such as voting age population, citizens voting age population and registered voters.

Incumbent protection: Drawing a district to aid the incumbent with reelection. [See "gerrymandering."]

Influence district: A district in which a racial minority does not have the ability to elect a candidate of choice, but makes up a substantial number of voters with the theoretical power to influence who wins the election.

Like-minded voters: Voters who by nature of their race, ethnicity, partisan affiliation, political philosophy or some other characteristic tend to vote for the same candidate.

Limited voting: A semi-proportional voting method used in several dozen U.S. jurisdictions in which oters cast fewer votes than there are seats to be elected, thereby allowing a majority group to control the majority of seats, but not all seats. The greater the difference between the number of seats and the number of votes, the greater the opportunities for fair representation.

Majority-minority district: District where a minority group composes a majority of the population. Also can be called "minority opportunity districts."

Method of equal proportions: Mathematical formula prescribed by federal statute that is used to reapportion congressional seats among the states after each decennial census.

Multi-member district: A district that elects more than one member to a legislature. Used for legislative elections in several states and thousands of local elections, although the number of legislators elected from multi-member districts has declined sharply over the past century.

Nesting: Redistricting method of creating two or more state lower legislative chamber districts that are completely contained within the boundaries of a state upper legislative chamber district.

One person, one vote: Constitutional principle based on Article I, Section 2 and the 14th Amendment which holds that each person's vote should count the same as every other person's vote. Under this principle each district within a jurisdiction should have the same or substantially the same population. This definition in fact suggests a right to districts with equal number of constituents rather than a right to districts with an equal number of voters. The standard for exact population equality is very strict for congressional districts, but less so for state and local government, with 10% population deviations permitted in state legislative districting.

P.L. (Public Law) 94-171: 1975 federal law that requires the U.S. Census Bureau to provide, each state with Census data that the states will need for redistricting. This data is typically provided by April 1st of each year following the completion of a census.

P.L. (Public Law) 105-119: 1997 federal law that requires the U.S. Census Bureau to make census data available to the public. This data is typically provided early in the year after the census is completed.

Packing: Consolidating a minority group's population into one district to give it more representation than is needed to create a majority in that district while reducing its presence, and electoral influence, in surrounding districts.

Perimeter: Ratio of the area of the district to the area of a circle with the same perimeter as the district. [See "compactness."]

Plurality: A percentage of votes that, although not being the majority, is the winning total because it is higher than all than any other candidate in an election received.  (Sometimes inaccurately called "first past the post," but there is no "post" or minimum level of support necessary to win.)

Polarization: Elections in which substantial grouping of voters in a district have overwhelmingly distinct preferences. Used when applied to racial group preferences as a condition for winning Section Two cases under the Voting Rights and often discussed in the context of distinct political preferences and concerns about excessive partisanship in legislatures.

Population: The total number of people, including noncitizens and children, who reside in a jurisdiction.

Preclearance: Review of a jurisdiction's redistricting plan by the U.S. Department of Justice or the U.S. District Court for the District of Columbia, clearing it as passing the standards set by Section 5 of the Voting Rights Act of 1965, as amended in 1982 and 2006. The preclearance process takes up to 60 days and if the DOJ objects to the change the state has three options: 1) accept the objection and modify its proposal; 2) as for a reconsideration; and 3) file suit in the U.S. District Court for the District of Columbia seeking a declaratory judgment that their proposal is valid under the VRA.  The Department over time has precleared more than 99% of all preclearance requests.

Proportional voting: A non-winner-take-all voting method used to elect legislators in a district with more than one seat. "Proportionality" describes the ability of like-minded voters to elect candidates in proportion to their share of the vote, not any guaranteed outcomes for any particular group of voters.

Racially polarized voting/racial bloc voting: Circumstances where the voting preferences of a particular group consistently vary from the preferences of other groups. When a white majority consistently defeats the preferences of a racial minority that is protected under the Voting Rights Act, a jurisdiction may need to change its district plan and/or electoral structure under Section 2 of the Voting Rights Act.

Reapportionment: Process of redistributing the number of seats in a jurisdiction's legislative body to the districts of that jurisdiction based on the results of the latest Census.  For example, due to particularly large population increases, Texas' congressional delegation will increase by four seats in 2012 while other states like New York and Michigan will lose seats following the 2010 reapportionment.

Redistricting: Process of redrawing the districts within a jurisdiction to reflect the results of the reapportioning process as well as the results of the Census; for example, congressional district boundaries may be changed to account for population shifts within a state.

Sampling:  Method of measuring a part of a population and extrapolating out to determine the full population.  This technique is not allowed for conducting the federal census.

Sections 2 and 5 of VRA: See "Voting Rights Act

Single-member district: A district that only elects one representative. Required for U.S. House district by a 1967 statute, not by the Constitution.

Submissions (VRA): Process that jurisdictions, which are covered by the VRA take in order to change their voting laws and district lines.  The process requires the jurisdiction to submit any to the Department of Justice and gives the DOJ sixty days to review the new plan.  The DOJ can object to the plan and the jurisdiction at that point has the option to accept the objection and modify the plan, ask for reconsideration or ask the District Court for the District of Columbia to overrule the DOJ.

Traditional districting principles: Term often used to refer to criteria, such as compactness and contiguity, which have historically been considered in drawing legislative or other districts.

Undercount: Error in Census data due to counting mistakes or inability to count some persons.

Voting age population (VAP): Number of persons in a geographic unit who are at least 18 years of age.

Voting Rights Act (VRA): Federal law prohibiting discrimination in voting practices on the basis of race or language group. [See also "Department of Justice"]

  • Section 2: Prohibits states and other jurisdictions from maintain voting laws, standards or practices that abridge the   right to vote on the basis of race or language group. Covers all parts of the United States.
  • Section 5: Requires that jurisdictions that have been determined to violate Section 2 and placed on a watchlist receive preclearance from the U.S. Department of Justice or the District Court for the District of Columbia for any changes to districts or other voting laws. Section 5 covers nine states and portions of seven others.


For more redistricting definitions, see:


Redistricting the Nation:

The Louisiana House:

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