Ranked Choice Voting and delayed runoff races are both multi-round systems that aim to promote majority support. Under these systems, a candidate reaches a majority once they have more than 50 percent of votes in the final round. Due to their nature, however, multi-round systems can result in fewer voters participating in the final round than the first one. Under RCV, this “ballot exhaustion” occurs when there are no more rankings to indicate a voter’s preference among the candidates still in the race. Under delayed runoffs, fewer voters participate in the final round due to a drop in turnout - in other words - voter exhaustion.
The table below compares RCV or "instant runoff" races with delayed runoff races. It analyzes election results from 84 RCV races over the past two decades from 10 cities (San Francisco, Oakland, San Leandro, and Berkeley, California; Minneapolis and St. Paul, Minnesota; Santa Fe, New Mexico; Takoma Park, Maryland; Telluride, Colorado and Portland, Maine) and the State of Maine’s 2018 Democratic gubernatorial primary and congressional primary and midterm elections. These are compared with the 221 congressional primary runoffs stretching back to 1994, and the 14 runoff races which took place in San Francisco from 2000-2003, before the city started using RCV.
As intended, both runoffs and RCV resulted in every winner having a majority of active votes in the final round. However, with RCV, the winner’s median share of the vote in the final round was 48.8 percent of the first round vote, as compared to delayed runoff winners’ median of 37.2 percent in congressional primary runoffs and 34.3 percent in the San Francisco runoffs.
The difference between RCV races and runoff races is even more evident when measured to 40 percent of the first round vote, the traditional measure of a “substantial plurality.” In the final round, more than 96 percent of RCV winners received 40 percent or more of the first round vote, while only 38 percent of the congressional primary runoff winners and 36 percent of San Francisco’s pre-RCV runoff winners achieved 40 percent of the first round vote. More than half of San Francisco’s 14 runoff winners earned fewer votes in the runoff than in the first round - a loss of support that cannot happen with RCV.
Last updated 2/21/19.