The Contextual Activation of Belief Networks
Cleavage Structures and Intersectional Bases

Partisanship lies at the heart of US politics. While most theories assume that party identities are shaped by existing social divisions in society, empirical research on the social basis of party identification has been relatively stagnant since the late 1990. This paper identifies two distinct ways in which partisan identities are rooted in social divisions: cleavage structures---capturing the depth and alignment of political cleavages---and intersectional bases---highlighting the political relevance of unique combinations of group memberships. We develop analytical tools to distinguish these forms empirically, which entails an (1) approach to analyze not only the depth of cleavages but also their alignment and (2) a model that overcomes the sparsity problem in analyzing the partisanship of a large number of intersectional categories. Analyzing the General Social Survey from 1977 to 2022, we find that while the depth of individual cleavages---especially race, religion and class---has increased over time, their alignment has weakened, producing growing cross-pressures rather than pressures in consistent directions. Furthermore, we show that political identities are increasingly shaped by the interaction of social divisions, with racial identity exerting divergent effects based on religion. Our findings underscore the growing complexity of the social roots of partisanship in the US and call for a shift from examining isolated cleavages to analyzing their alignment and intersections.