The Ideological Polarization of State Party Platforms from 1960-2020

• In Event: New Methodological Approaches in State Politics Research

Abstract

Political parties form a crucial representational link between the preferences of the mass public and the platforms of candidates and elected officials. However, scholars have lacked knowledge about the ideological positions of state parties. In this project, we draw from a large corpus of over 2,000 state party platforms in the United States from 1960-2020. First, we manually code each state party’s positions on approximately 200 public policy issues, such as abortion, gay rights, environmental protection, and gun control. We then use a Bayesian latent variable model to scale the ideology of each state party on a one dimensional spectrum. We also examine the dimensionality of state party platforms by producing separate scales on the economic and cultural domains. In addition, we place state party platforms into a common space with the liberalism of state policies from Caughey and Warshaw (2016). We use these new scores to examine changes in polarization and the nationalization of state party platforms over the past sixty years. We also investigate whether state parties’ platforms are responsive to changes in their electorates. Finally, we examine whether each state’s policies are more congruent with the positions of Democrats or Republicans in their state, and how this has changed overtime.

Authors

• Christopher Warshaw, George Washington University

• Matthew Carr, Columbia University

• Justin Phillips, Columbia University

• Gerald Gamm, University of Rochester