Fragmentation Without Cleavages? Endogenous Fractionalization In The Brazilian Party System

This article investigates the causes of party system hyperfragmentation in Brazil. We ask why hyperfragmentation-understood as extreme multipartism that continues to fractionalize-occurs despite significant changes to social cleavages or to electoral rules. Using survey data from federal legislators, we rule out the possibility of new issue-based multidimensionality. Using new estimates of the ideological position of legislative parties, we show that new party entry was not driven by polarization or convergence among traditional parties. We advance an alternative explanation of "fragmentation without cleavages," arguing that changing dynamics of electoral list composition, federal party funding, and coalition management have changed the context of political ambition. For strategically minded elites, it is more attractive than ever before to be a dominant player in a small party.