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Colin Case

PhD Candidate, expected graduation in May 2024

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Candidate Differentiation in Congressional Elections (Treul, Hetherington, Olivella, Roberts, Ryan). In modern congressional elections, the overwhelming majority of districts are considered safe, with only one political party having a viable chance of winning in the general election. As a result, partisan primary elections serve as the main arena for potential electoral competition. But members and candidates in these elections cannot rely on party brands to gain voters’ support; they must be strategic about the ways in which they differentiate themselves from co-partisans to maximize their electoral chances and convey information about their candidacy to voters. My dissertation and broader research agenda focus on the ways in which candidates respond to these electoral dynamics in primary elections, as well as the implications of this behavior as it relates to election outcomes, lawmaking, polarization, and representation. In pursuing this research, I develop and employ advanced computational methods to assess candidate and member behavior in Congress with a particular interest in high-quality measurement. My job market paper uses an original data set of over 45,000 issue statements from about 6,000 primary candidates who ran in the 2018, 2020, and 2022 congressional primaries. Using this data, I assess the extent to which incumbent candidates respond to the positioning of primary challengers. While previous research has tested this hypothesis, there has been a lack of evidence that incumbents respond to the positioning of primary challengers. I argue this is due to the use of aggregate measures of positioning that focus on legislative behavior rather than campaign positioning. From candidates’ campaign issue positions, as presented on their campaign website, I develop a new measure of candidate positioning using word embeddings. This new measure both increases the number of candidates with an issue position when compared with existing measures, as well as captures actual campaign behavior instead of approximations of campaign behavior. With this measure, I show incumbent candidates do respond to the positioning of primary challengers and become more extreme (moderate) in their issue positions in response to an extreme (moderate) primary challenger.

Research Interests

  • American Politics
  • Political Methodology


Political Behavior, Journal of Political Marketing