Constituency Congruency and Candidate Competition in Primary Elections for the U.S. House

Abstract

Previous research on congressional elections has largely concluded that House elections have become much less competitive in the modern era. Our research investigates one area where we should theoretically expect to observe more competition ﾖ namely, primary elections. In this paper, we examine when and where a state legislator will emerge to run in a congressional primary. All else equal, we expect that state legislators who can carry a large portion of their old state reelection constituency to the 'geographic' congressional constituency will be more likely to emerge and receive a higher vote share in the election. Using GIS software, we are able to derive a measure of constituency overlap by focusing on the degree of congruency between state legislative and congressional districts. Our results indicate that state legislators are more likely to emerge in a primary if constituency congruency is relatively high, especially in open seat contests. When state legislative candidates start with a strong voter base, we also find that they do better in the primary election.

Keywords: Congress, primary elections, representation