Heterogeneous Party Activists, Intra-Party Dynamics and Electoral Performance

How do heterogeneous party activists shape a party’s trajectory? Preference heterogeneity within a party and factional struggles impact the programmatic commitments of parties and their external strategy formation in inter-party competition. While most of the literature on intra-party politics conceives of parties as oligarchic micro-polities dominated by their leaders, we know less about the effects of entry-exit dynamics within parties. This study posits that the party capture of the most successful German newcomer party, the Alternative für Deutschland (AfD), has contributed to the party’s persistence. Its rapid transformation from an elitist Eurosceptic platform to a populist radical right party offers a unique opportunity to study the dynamics of heterogeneous activists and their impact on electoral success in a multi-party system. Linking pre- and post-transformation data of individual party activists to micro-spatial data indicating their social and economic origin, we first show that the composition of activists significantly changed in the course of the party’s formative period. Exploiting the quasi-random variation in ballot options in a German state election, a difference-in-difference design establishes that this party capture decisively contributed to the party’s success. In highlighting the permeable boundaries of parties, our analysis sheds light on the significance of horizontal divides in intra-party politics for inter-party competition.