Do Divisive Primaries Hurt Parties? Evidence from Mexico

• In Event: Parties, Party Systems and Partisanship in Latin America

Abstract

We study the effect of primary election divisiveness on general election outcomes in Mexico. Although an extensive literature in American politics has documented evidence that divisive primary elections hurt political parties’ electoral performance, it is unclear whether these findings generalize to other settings. Using an original dataset on legislative primaries at both the federal and the state levels, we find that divisive primaries–measured as those in which the candidate won by a narrow margin–do not affect the party’s electoral performance. However, our results show that the party leaders’ interference in favor of a primary aspirant can create or exacerbate internal divisions, and even trigger party defections, significantly hurting the electoral prospects of the party’s eventual nominee. Our findings have important implications for political parties in developing countries, many of which increasingly conduct primary elections but lack the resources or institutions to guarantee that all aspirants will be treated equally.

Author

• Sergio J Ascencio, University of Essex