This page provides a brief summary of my Cambridge Element with Ted Carmines and Paul Sniderman. The book provides more context, but here’s the argument and core empirical findings:
Our work explores the politics, not simply the psychology, of mass polarization in the United States. We theorize that when people know and share their party’s ideological orientation, parties are more than emotional labels — they are frameworks for developing coherent, holistic belief systems about political issues.
Using 50 years of public opinion data, we document multiple empirical implications of this theory. Our principal finding is that polarization is circumscribed – and for all intents and purposes, confined – to Republican and Democratic identifiers that know and share their party’s ideological orientation.
In the process, we draw other, equally provocative conclusions. For example:
- Since the early 1970s, the percent of matched partisans in the electorate – partisan identifiers that know and share their party’s ideological orientation – has increased markedly. For an increasing number of Americans, partisan politics is ideological politics.
- However, the percent of Republicans that fully match their party’s ideology has consistently outpaced the percent of Democrats that do. To that extent, a competitive imbalance is wired into the party system.
- Domain sorting, not just issue sorting, describes how the parties’ core supporters have polarized. Polarization on social welfare issues has been symmetrical, Republican and Democratic identifiers polarizing at about the same time and pace. Yet polarization on cultural and racial issues is often asymmetrical, one party’s supporters polarizing much earlier than the other’s.
- For example, among non-Hispanic whites, Republican identifiers polarized on racial issues at least 30 years earlier than Democratic identifiers. This polarization lag potentially helps explain Republicans’ continued electoral successes at the national level.
- For partisans that know and share their party’s ideology, affect and belief are two sides of the same coin. For matched partisans, the relationship between affective polarization and policy attitudes has strengthened as the parties in government have polarized. For traditional partisans, this relationship is weaker or non-existent.
In other words, partisanship today means different things to different people. For more than half of partisan identifiers, parties serve – for better or worse – as models of what it means to hold coherent, well-organized political beliefs. For the rest, partisanship is an emotional commitment but not much more.
Ultimately, we recommend that scholars fundamentally rethink both the concept and measurement of party identification, to reflect the difference between ideological and traditional partisans.
Ted, Paul, and I loved working on this project — and we hope that our work inspires continued debate about the meaning of both party identification and partisan polarization in the U.S. context.
Eric R. Schmidt, PhD 