The Plurality Problem: Plurality Primary Victors Hurt Parties in General Elections (WP-24-07)
Laurel Harbridge-Yong and Rachel Hutchinson
Most states do not have majority thresholds for primary elections, which means that “plurality primary victors” (who won the primary with less than 50% of the vote) often advance to the general election. Harbridge-Yong and Hutchinson examine whether plurality primary victors harm their party in general elections. Building on the divisive primaries literature, of which “plurality primaries” share several characteristics and likely mechanisms, they hypothesize that candidates who win their primary election with a plurality of votes perform worse than majority primary victors, relative to expectations. They examine U.S. House, U.S. Senate, and gubernatorial partisan primaries from 2010–2022 in which three or more candidates ran. The researchers find that plurality primary winners underperform relative to expectation and that in competitive districts, this translates into a reduced likelihood of winning the general election. They conclude by discussing how potential reforms, such as ranked choice voting (RCV), might change the partisan and representational consequences of plurality primaries.