The Group Basis of Partisan Affective Polarization

What explains rising partisan animosity in the United States? We argue that mass partisans' feelings toward the social group coalitions of the parties are an important cause of rising affective polarization. We first leverage evidence from the American National Election Study (ANES) Time Series to show that partisans' feelings toward the social groups linked to their in-party (out-party) have grown more positive (negative) over time. We then turn to the 1992-96 and 2000-2004 ANES Panel Surveys to disentangle the interrelationship between partisan polarization and social group evaluations. Individuals with more polarized social group evaluations in 1992 or 2000 report substantially more polarized party thermometer ratings and more extreme, and better sorted, partisan identities four years later. Notably, these variables exerted little reciprocal influence on group evaluations. Our study has important implications for understanding affective polarization and the role of social groups in public opinion.