Tracing Polarization’s Roots: A Panel Study of Voter Choice in Congressional Primary and General Elections (Revise and resubmit, American Journal of Political Science; first author)
with David E. Broockman, Gregory A. Huber, and Joshua L. Kalla

Competing theories alternatively blame congressional polarization on interest group control over nominations, extreme and highly-knowledgeable primary voters, or uninformed general electorates.  We argue that these actors all prefer policy-aligned candidates, but that primary voters face unique challenges electing them because of the absence of distinguishing part 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; difficulty distinguishing candidates from partisan reputations is a likely mechanism. Consistent  with  group  influence,  learning  endorsements  meaningfully  affects  voter choice.  Our findings shed new light on why congressional candidates fail to converge to the median voter.

The US House of Representatives is experiencing historic levels of polarization. One possible explanation is that as parties have become ideologically sorted, primary voters have nominated more extreme candidates to general elections. This leaves the general electorate, even in competitive districts, with a choice between two extreme candidates. However, not only has existing empirical research found limited evidence that House primary voters have contributed to polarization, there is only weak evidence that ideology factor into voting decisions in House primaries at all. I argue that this could be due to a lack of survey data on House primary voters limiting the types of analyses that can be examined. To remedy this, I ran two-wave panel surveys during the 2022 and 2024 US House primary cycles, enabling the creation of a first-of-its-kind dataset of 9,152 primary voters from 40 primaries in 10 states. This paper uses that dataset to investigate ideological voting in US House primaries and finds robust evidence of its prominence.

Strategic Discrimination Against Women in US House Primaries with Sara Jozer and Anna Mikkelborg

A robust finding in American politics literature is that “when women run, women win.” However, this result is characteristic only of general elections, ignoring a likely mechanism behind the systematic underrepresentation of women in government: strategic discrimination in primaries. Recent research defines strategic discrimination as a bias against voting for women candidates in primary elections because of a belief that general election voters are less likely to vote for a woman candidate, and that, therefore, nominating a woman reduces their party’s chances of winning the general election. This is distinct from overt discrimination or hostile sexism, because reluctance to vote for a woman in a primary election is not rooted in one’s personal bias, but in a belief that others hold a personal bias against women candidates. To date, studies of strategic discrimination have focused on the 2020 presidential primary, which has limited analysis to a single race and to voters in the Democratic Party. Leveraging data from an original survey conducted during the 2024 US House primary elections, we find evidence that strategic discrimination disadvantages women in congressional elections.