ORI GIN AL PA PER Party Polarization and Mass Partisanship: A Comparative Perspective

Abstract Scholars view polarization with trepidation. But polarization may clarify voters ’ choices and generate stronger party attachments. The link between party polarization and mass partisanship remains unclear. I look to theories of partisanship to derive implications about the relationships among polarization, citizens ’ per-ceptions of polarization, and mass partisanship. I test those implications using cross-national and longitudinal survey data. My results confirm that polarization corre-lates with individual partisanship across space and time. Citizens in polarized systems also perceive their parties to be more polarized. And perceiving party polarization makes people more likely to be partisan. That relationship appears to be causal: using a long-term panel survey from the United States, I find that citizens become more partisan as they perceive polarization increasing. Keywords Party polarization Mass partisanship CSES ANES Panel survey Party polarization poses serious problems for democracy. Studies link the polarization of the Democratic and Republican Parties in the United States to legislative gridlock, elite incivility, income inequality, and mass disengagement.1 Across a broader range of countries, polarization also contributes to democratic Electronic supplementary material The online version of this article (doi:10.1007/s11109-014-9279-z) contains supplementary material, which is available to authorized users