Issues, Endorsements, and Vote Choice: A Panel Study of Congressional Primary and General Elections

Why do congressional candidates' platforms diverge from the median voter? Prevailing theories blame general election voters' ignorance, extreme primary voters, and organized groups. We argue that *primary* voters face challenges electing policy-aligned candidates because primaries lack distinguishing party cues. We report an original four-wave panel survey ($N=31,254$) spanning primary and general elections in 27 congressional districts in 2024, supplemented with candidate position and endorsement information. The findings support our argument. Both primary and general election voters are ~14 percentage points more (less) likely to vote for a candidate after learning they (dis)agree with them on an issue. However, primary voters know less than general election voters about which candidate is closest to them. General election voters appear to more successfully select aligned candidates by inferring candidate positions from party reputations. Group endorsements may also affect choices. Our findings shed light on why candidates fail to converge to the median voter.