Within-Party Discord and Polarization

In the literature on polarization, it is axiomatic that hostility and negative affect between groups are heightened by within-group homogeneity. However, this paper explores two mechanisms leading to the opposite conclusion for political parties in democracies. First, when voters are risk-averse, negative affect toward out-parties should increase with their internal heterogeneity. Second, party heterogeneity facilitates “false polarization,” whereby party elites convince supporters to judge the out-party by its most extreme members. We use cross-country survey data from around the world to demonstrate that more heterogeneous parties are the objects of greater misperception and negative affect. Affective polarization is associated not with homogeneous parties that commit to rigid, fixed platforms, but rather, by heterogeneous parties whose fissiparous tendencies can be exploited by their opponents.