Congressional and Presidential Primaries: Open, Closed, Semi-Closed, and Others

Last updated July, 2015. Presidential primary data last updated June, 2012.

Overview:

This page details information about the main categories of congressional primaries in the United State (open, closed, semi-closed, and others) and puts each state into one of these categories. We also include information regarding the type of presidential primary or caucus held in each state. In addition to the map below, check out our interactive map at the bottom of this page.

Much of the rules listed here can be changed by an internal political party process. Consequently, sometimes one political party will use one process while another political party uses a different process. This sometimes makes it difficult to track changes. This information is as up-to-date as possible as of July 2015. However, states and parties regularly make changes to their primary or caucus rules. If any of the information below has changed, please email us at info [at] fairvote.org and we will review our information and update it, if appropriate to do so.

Also note that the categories listed here are broad. States employ a variety of rules, so be sure to look at the "Remarks" column for your state.

Open Closed Primaries

Open primary:

In an open primary, voters of any affiliation may vote in the primaries of any party they choose. They cannot vote in more than one party's primary, although that prohibition can be difficult to enforce in the event a party has a primary runoff election. In many open primary states voters do not indicate partisan affiliation when they register to vote.

One area of contention in open primaries is "crossover" voting. It most often involves voters affiliated with one political party voting in the primary of another political party to influence the other party's nomination. For example, if a district routinely elects the Democratic nominee, Republican voters may attempt to swing the Democratic primary election toward a more conservative nominee. Occasionally, there also are concerns about sabotage, or "party crashing," which involves partisans strategically voting for a weaker candidate in another party's primary in the hope that the opposition party will nominate a candidate who is easier to defeat in the general election.

Closed primary:

In a closed primary, only voters registered with a given party can vote in that party's primary. States with closed primaries include party affiliation in voter registration so that the state has an official record of what party each voter is registered as.

Closed primaries preserve a party's freedom of association by better ensuring that only bona fide members of the party influence who that party nominates, but critics claim that closed primaries can exacerbate the radicalization that often occurs at the primary stage, when candidates must cater to their party's "base" rather than the political center.

In a few states, independent voters may register with a party on Election Day. However, they must remain registered with that party until they change their affiliation again.  A handful of states even allow voters registered with one party to switch their registration at the polls to vote in another party's primary. In these rare instances, a closed primary can more closely resemble open or semi-closed primaries than the closed primaries of other states. Such states are still considered "closed," however, so be sure to refer to the "Remarks" column for your state to see if that is the case.

Semi-closed primary:

In a semi-closed primary, unaffiliated voters may choose which party primary to vote in, while voters registered with a party may only vote in that party's primary. Representing a middle ground between the exclusion of independent voters in a closed primary and the free-for-all of open primaries, the semi-closed, primary eliminates concerns about voters registered  in other parties from "raiding" another party's nominating contest.

People who align with a given party may theoretically still vote in another party's primary if they are registered as independent. The potential for such tactical party registration is also present in the strictest of closed primaries.

Other:

In addition to the above three broad categories, some states use one of the following methods to nominate candidates for Congress:

Top Two

Under "Top Two," political parties do not nominate candidates at all. Instead, all candidates, regardless of party affiliation, run on the same primary ballot. The top two vote-getters then face off in the general election, again regardless of party affiliation. This means that the general election always has exactly two candidates on the ballot, and those two candidates may be from different political parties or from the same political party.

California and Washington use Top Two for state and congressional offices. Nebraska uses a Top Two system but without party labels on the ballot at all for the election of its nonpartisan state legislature. 

Top Two should not be confused with "open primaries." Open primaries retain partisan nomination while allowing any voter to participate in the nomination process for any party. By contrast, the top two system eliminates party primaries altogether, with the field winnowed regardless of candidates' party affiliation.

The Louisiana System

The Louisiana system, sometimes called the "Cajun Primary," eliminates the primary election altogether. Instead, all candidates, regardless of party affiliation, run on the same ballot in November. If a candidate receives more than half of the votes, that candidate is elected. If no candidate wins with a majority, the top two vote-getters face off in a December runoff election. Qualified absentee voters receive a ballot for the November election and a ranked ballot for the December runoff, so that they can vote as normal in the general election and then have their ranked ballot count for whichever runoff candidate they ranked highest in the runoff election.

This system mirrors a nonpartisan runoff election process used in many local elections, except with the use of party labels. Although Louisiana law refers to the election in November as the "primary" and the December runoff as the "general" election, the November election takes place on the federally mandated Election Day, and most candidates win office by receiving a majority vote in that election, so it is best understood as a general election, with the December election as a contingent runoff.

The Louisiana system is sometimes mistakenly equated with the Top Two system, but holding the first election in November and electing any candidate with more than 50% of the vote in that election makes it sufficiently distinct that it should not be understood as a mere variant of Top Two.

Blanket Primaries

Alaska is now the only state that continues to use a blanket primary. Under a blanket primary, all candidates, regardless of party affiliation, run on the same primary ballot. Then, the single candidate with the most votes from each political party will be that party's nominee in the general election. The Supreme Court ruled in 2000 that states cannot require political parties to participate in a blanket primary. In Alaska, all parties except the Republican Party voluntarily participate in the blanket primary. The Republican Party has its own primary ballot, which uses semi-closed primary rules.

List of states:

The following is a list of states by type of primary election, last updated July, 2015.

State

Closed

Open

Semi-Closed

Other

Source

Remarks

Presidential Primary or Caucus

Alabama

 

x

 

 

Ala. Code § 17-13- 7

No party affiliation required at registration. 

Open

Alaska

 

 

 R

 D

Alaska Stat. §§ 15.25.014, 15.25.060

Only registered Republicans, Independents, or Unaffiliated voters can vote in the GOP primary. All other parties appear on a blanket primary.

Open

Arizona

 

 

 x

 

Ariz. Rev Stat § 16-467; Ariz. Att'y Gen. Op. No. I99-025 (R99-049)

Voters registered as independent, no party preference or members of a party without ballot recognition may vote in the partisan primary election of their choice. Voters registered in a recognized political party may vote only the primary election ballot for their political party.

Closed

Arkansas

 

x

 

 

Ark. Code Ann. § § 7-7-306- 308

No party affiliation required at registration.

Open

California

 

 

 

x

Proposition 14; CA S.B. 28

California uses "Top Two."

R: Closed; D: Semi-Closed

Colorado

 x

 

 

 

Colo. Rev. Stat. § 1-7-201

Only voters affiliated with a particular party may vote in its primary, but unaffiliated voters may declare their affiliation at polling place and vote in a party primary.

Closed

Connecticut

x

 

 

 

Conn. Gen. Stat. §§ 9-431, 9-59

Parties may choose to allow for semi-closed elections if they make a change to their party rules; however, as of now, the primaries remain closed.

Closed
Delaware x       Del. Code Ann. § 3110 Only voters affiliated with a particular party may vote in its primary. Closed
District of Columbia x       D.C. Code Ann. § 1-1001.09(g)(1); 1-1001.05(b)(1) Closed primary for D.C. elected officials such as Delegate, Mayor, Chairman, members of Council, and Board of Education. Unregistered voters can register to vote and choose a party on a primary Election Day, whereas registered voters with no party affiliation cannot affiliate on Election Day.  

Florida

x

 

 

 

Fla. Stat. Ann. § 101.021

Only voters affiliated with a particular party may vote in its primary. All registered voters, including those without party affiliation, are entitled to receive non-partisan ballots and vote in local elections that may be held in conjunction with a primary.

Closed

Georgia

 

x

 

 

Georgia Code Ann. § 21-2-224

No party affiliation required at registration. However, on Election Day, voters must declare an oath of intent to affiliate with the particular party for whom they are voting on Election Day.

Open

Hawaii

 

x

 

 

Haw. Rev. Stat § 12-31

Voters receive a single ballot with the primary contests for each party listed in its own column. Voters may vote in any party column without declaring affiliation, but they may not participate in more than one party primary.

R: Open; D: Closed

Idaho

 R

 D

 

 

Idaho Code Ann. § 34-904A

Until 2011, all Idaho primaries were open. After the GOP obtained a declaratory judgment that mandating open primaries violated freedom of association and was thus unconstitutional, the legislature passed a bill allowing parties to choose which type of primary they use. The Democrats use open primary rules: any voter can request the Democratic ballot. The Republicans use closed primary rules, but any voter can change their affiliation to Republican at any time including on election day.

R: Closed; D: Open

Illinois

 

 x

 

 

10 Ill. Comp. Stat. 5/7-43, -45

No party affiliation required at registration. Voters declare their party affiliation at the polling place to a judge who must then announce it "in a distinct tone of voice, sufficiently loud to be heard by all persons in the polling place." If there is no "challenge," the voter is given the primary ballot for his or her declared party.

Semi-Closed

Indiana

 

x

 

 

Ind. Code §§ 3-10- 1-6, 1-9

No party affiliation required at registration. Classified as a "modified open" primary." A voter must have voted in the last general election for a majority of the nominees of the party holding the primary, or if that voter did not vote in the last general election, that voter must vote for a majority of the nominees of that party who is holding the primary. However, there is really no way to enforce this, and cross-over occurs often. The same modified open primary is used for the presidential primary.

Open

Iowa

 x

 

 

 

Iowa Code Ann. §§ 43.38; 43.42

Only voters affiliated with a particular party may vote in its primary; however, voters may change party on the day of the primary election.

Closed

Kansas

x

 

 

 

Kan. Stat. Ann. §§ 25-3301

Voters affiliated with a major party on election day may only vote in that party's primary. Unaffiliated voters may affiliate with either the Democratic or Republican party on election day but may not vote in either primary and remain unaffiliated.

Closed

Kentucky

x

 

 

 

Ky. Rev. Stat. Ann. § 116.055

Only voters affiliated with a particular party may vote in its primary.

Closed

Louisiana

 

 

 

x

La. Rev. Stat. Ann. §§ 18:1280.21

No party affiliation required at registration. Louisiana holds no primary election for congressional elections. Instead, all candidates seeking office appear on the general election ballot in November. If a candidate receives  a majority vote, they are elected. If not, a runoff election between the two candidates with the most votes occurs in December.

Closed

Maine

x

 

 

 

Me. Rev. Stat. tit. 21, §§ 111, 340

By party rules, only voters affiliated with a particular party may vote in its primary.

Closed

Maryland

x

 

 

 

Md. Code, Elec. Law §§ 3- 303, 8-202

Parties may choose to hold open primaries, but must notify the State Board of Elections six months prior.

Closed

Massachusetts

 

 

x

 

Mass. Gen. Laws ch.53 §37

Affiliated voters must vote in the primary of their party; however, unaffiliated voters may vote in either primary while remaining unaffiliated.

Semi-Closed

Michigan

 

x

 

 

Mich. Comp. Laws § 168.575; Public Act 163

Voters do not have to declare a political party to vote; but must vote for all one party once they enter the voting booth.

Open

Minnesota

 

x

 

 

Minn. Stat. § 204D.08

No party affiliation required at registration.

Open

Mississippi

 

x

 

 

Miss. Code Ann. § 23-15-575

No registration by party affiliation. 

Open

Missouri

 

x

 

 

Mo. Rev. Stat. § 115.397

No party affiliation required at registration.

Open

Montana

 

x

 

 

Mont. Code Ann. § 13-10-301

No party affiliation required at registration. Each voter has the choice which ballot to use on Election Day.

Open

Nebraska

 

 

x

 

Neb. Rev. Stat. § 32-912

For federal elections, affiliated voters must vote in the primary of their party; however, unaffiliated voters may vote in either primary. For partisan state-level elections, unaffiliated voters may vote in the Democratic primary but may not vote in the Republican primary.

Semi-Closed

Nevada

x

 

 

 

Nev. Rev. Stat. §§ 293.287, 293.518

Only voters affiliated with a particular party may vote in its primary.

Closed

New Hampshire

 

 

 x

 

N.H. Rev. Stat. Ann § 659:14

Closed primaries in effect; but the statute allows for semi-closed primary if that party's rules allow for it. Unaffiliated voters must affiliate to vote in a primary, but can subsequently unaffiliate by filling out a form. Unregistered voters can register at the polls.

Semi-Closed

New Jersey

x

 

 

  N.J. Stat. Ann. § 19:31-13.2 

Only voters affiliated with a particular party may vote in its primary. Newly registered voters voting in their first New Jersey primary may choose an affiliation at the polls.

Closed

New Mexico

x

 

 

 

N.M. Stat. §1-12-7.2

Parties may choose to allow for semi-closed elections if they make a change to their party rules; however, as of now, the primaries remain closed.

Closed

New York

x

 

 

 

N.Y. Elec. Law § 5-304

Only voters affiliated with a particular party may vote in its primary.

Closed

North Carolina

 

 

 x

 

N.C. Gen. Stat. §§ 163-59, -119

State law provides for closed primaries, but both parties allow unaffiliated voters to choose their ballot on election day.

Semi-Closed

North Dakota

 

x

 

 

N.D. Cent. Code, § 40-21-06

The only state without voter registration. 

R: Closed; D: Open

Ohio

 

x

 

 

Ohio Rev. Code Ann. § 3513.19

Party affiliation not required upon registering. You may vote the primary ballot of the political party with which you currently wish to be affiliated. If you voted the primary ballot of a different political party, you will complete a statement at your polling place confirming the change in your political party affiliation.

Open

Oklahoma

R

 

 D

 

Okla. Stat. §26-1-104

Both major parties used closed primaries until July, 2015, when the Democratic Party announced that it would allow unaffiliated voters to participate in their primaries. Closed

Oregon

x

 

 

 

Or. Rev. Stat. §§ 247.203, 254.365

The primary remains closed for the presidential and legislative elections. However, as of February 2012, the Oregon Republican Party voted to open the Republican primary to unaffiliated voters for the offices of secretary of state, attorney general, and treasurer.

Closed

Pennsylvania

x

 

 

 

25 Pa. Stat. Ann. § 2812

Only voters affiliated with a particular party may vote in its primary.

Closed

Rhode Island

 

 

x

  R.I. Gen. Laws §§ 17-15-24

An unaffiliated voter for the past 90 days may designate his or her party affiliation on election day by voting for that party in the primary.

Semi-Closed

South Carolina

 

x

 

 

S.C. Code Ann. §§ 7-13-610, 7-13-1010

No party affiliation required at registration, but voters must take an oath affirming they have not voted in any other primary.

Open

South Dakota

R

 

D

 

S.D. Codified Laws § 12-6-26

Parties may choose to allow for semi-closed elections. Democrats have opened up their primaries to allow unaffiliated voters to vote. R: Closed; D: Open

Tennessee

 

x

 

 

Tenn. Code Ann. § 2-2-102 

No party affiliation required at registration, but the voter must affiliate at the primary polling location or declare their allegiance to the party (much like Mississippi's loyalty oath).   Open

Texas

 

x

 

 

Tex Elec. Code Ann. § 172.086

No registration by party; voters are not held to affiliation of past election. Each year, voters have a clean slate and must choose on primary day whether to vote by a party affiliation or as unaffiliated; voters are held to that affiliation in the runoff. For the presidential primary, it is the same system as of December 19, 2011.

Open

Utah

 R

 

 

Utah Code Ann. §§ 20A-2-107.5

Utah uses a combination of party conventions and a primary election. The primary is closed for Republicans and semi-closed for Democrats.

R: Closed; D: Open

Vermont

 

x

 

 

Vt. Stat. Ann. tit. 17, § 2363

No registration by party. For presidential primary, voters must declare which ballots they want.

Open

Virginia

 

x

 

 

Va. Code Ann. § 24.2-530

No party affiliation required at registration. Under some circumstances a political party may not participate in the primary, in which case they will nominate by some other method that may be closed or semi-closed.

Open

Washington

 

 

 

x

Wash. Rev. Code § 29A.52.112, 29A.36.171

Washington uses the Top Two system.

R: Closed; D: Semi-Closed

West Virginia

 

 

x

 

W. Va. Code § 3-5- 4

Technically a closed system, but all parties allow any voter who is not registered with an official party to request their ballot for the Primary Election.

Semi-Closed

Wisconsin

 

x

 

 

Wis. Stat. § 6.80

No party affiliation required at registration.

Open

Wyoming

 x

 

 

 

Wyo. Stat. Ann. § 22-5-212

A voter can change his or her party affiliation on election day.

Closed