Press Release: San Francisco Mayoral Election By the Numbers: A First Look

Posted by Pedro Hernandez on June 06, 2018


June 5, 2018

Contact: Pedro Hernandez at [email protected] or 415.613.2363

San Francisco Mayoral Election By the Numbers: A First Look
Trends Suggest Voters Using RCV Better Than Ever More San Francisco Voters for Mayor than for Governor and Far Less Error

SAN FRANCISCO -- First ranked choice voting (RCV) election results in the special election for mayor of San Francisco suggest that voters are handling ranked choice voting ballots well. After analyzing the first release of the 78,223 ballots received by the Board of Elections on June 4, FairVote California finds that San Francisco voters are continuing to make effective use of ranked choice voting.

  • Voters handle RCV ballots for mayor better than non-RCV ballots for governor. In the early election results for governor, there are 1,909 overvotes that invalidated ballots, which is a rate of greater than 2.4 percent. In the early election results for SF Mayor, there are only 223 overvotes, a rate of less than 0.3 percent. In other words, a voter was eight times more likely to make an error on their non-RCV ballots for governor than their RCV ballots for mayor. About the same number of voters skipped both contests. Of all 79,024, voters mailing in ballots that arrived before Election Day, 77,370 had their vote count for mayor. Only 75,638 had their vote count for governor.

  • Voters far more likely to vote for mayor than for U.S. Senator: Of all voters mailing in ballots before Election Day, 77,370 had a vote count for mayor with an RCV ballot. Only 74,315 had a vote count for U.S. Senator, with 4,175 skipping the contest entirely with a non-RCV ballot.This is part of a pattern where city voters are more likely to vote in city elections with RCV than they were in pre-RCV elections.

  • High retention of voters: The percentage of voters having their ballot count in every round is higher than ever, with nearly nine in ten voters counting in every round from first to the last. In traditional runoff elections, turnout declined on average by more than 30 percent.

“These numbers are preliminary, however they underscore findings from our recent report that San Francisco voters have effectively used ranked choice voting -- and it’s getting even better,” said FairVote California Deputy Director Pedro Hernandez. “Voters were more engaged in the election for mayor than for other key races, and were more likely to have their vote count for mayor than for governor or U.S. Senator.


This initial release of data is only based on vote-by-mail ballots that the Department of Elections (DOE) received and processed before Election Day. Based on an analysis of the mayoral race in 2015, that means that this likely reflects less than half of the final vote.

Soon after 9 pm, the Department of Elections released its first preliminary report of ranked choice voting results of vote-by-mail voters. Tonight, London Breed narrowly leads Mark Leno in the final round of the ranked choice voting election, but the results remain too close to call.

“Of the votes counted so far, 64,133 (83 percent) of voters ranked 2-3 candidates, showing that San Francisco voters are engaging with the ranked choice voting system,” Hernandez said. “RCV empowers San Franciscans to vote for the candidates they prefer without fear of wasting their vote.”

Notably, the speed of releasing results is purely a factor of how many ballots the DOE has to process, not ranked choice voting. Once the DOE has processed a batch of ballots, it can run the RCV tabulation on that batch and release those results in about an hour, according to Director John Arntz. Next year, with its new voting machines in place, even that one hour interval to run the RCV tabulation will not be necessary -- it will essentially be instantaneous.

FairVote California and FairVote will be analyzing results tonight and in the days ahead. For comment, please contact FairVote California Deputy Director Pedro Hernandez at [email protected].

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