Partisan Moods: Polarization and the Dynamics of Mass Party Preferences

Inquiry into the origins of partisan polarization has generally treated polarization as a simple, symmetric phenomenon-the degree to which the worldviews of the mass Democratic and Republican parties have or have not diverged from one another. In this article, we disaggregate polarization into its constituent parts, the dynamic preferences of the mass Democratic and Republican Parties. This approach allows for the possibility that intraparty dynamics may influence interparty differences and for the integration of studies of polarization with literatures addressing other dynamics in aggregate public opinion. Building on individual-level research on partisan identities and macrolevel research on public mood, we argue that party polarization may be catalyzed, in part, by the mass parties' differential responsiveness to changes in the macro political-economic context. We find support for this position, showing asymmetries in the dynamics of polarization that are associated with differential partisan responsiveness to domestic policy choices.