Losing predicts perceptions that elections were decided by fraud, but margin of loss and candidate race do not

Which factors cause citizens to think that an election was determined by fraud? Fraud beliefs have been shown to be more common among supporters of losing candidates. In the current U.S. context, fraud beliefs are also higher among Republicans than Democrats. However, we know less about the roles of electoral margin and candidate race. Beliefs that candidates won due to fraud might be more likely in closely contested elections, where small shifts in vote share could be decisive, or when non-white candidates defeat white candidates given perceived associations between race and crime or corruption. We examine these questions with a unique survey in which a nationally representative sample (n $=$ 2896) reported their beliefs about the legitimacy of a random subset of 2022 U.S. House election outcomes. Our results indicate that Republican participants are far more likely than are Democrats to believe that House election results were determined by fraud, and that the partisan gap is larger for contests the GOP candidate lost. However, we do not find convincing evidence that these perceptions were driven by the margin by which the losing candidate was defeated or the apparent race of the candidates. These results suggest that party is the dominant factor in perceptions of election legitimacy, trumping losing vote margin and candidate race.