The Ideological Nationalization of Mass Partisanship: Policy Preferences and Partisan Identification in State Publics, 1946–2014

Since the mid-20th century, elite political behavior has increasingly nationalized. In Congress, for example, within-party geographic cleavages have declined, roll-call voting has become increasingly one-dimensional, and Democrats and Republicans have diverged along this main dimension of national partisan conflict. The existing literature finds that citizens have displayed only a delayed and attenuated echo of elite trends. We show, however, that a very different picture emerges if we focus not on individual citizens but on the aggregate characteristics of geographic constituencies. Using estimates of the economic, racial, and social policy liberalism of the average Democrat, Independent, and Republican in each state-year 1946–2014, we demonstrate a surprisingly close correspondence between mass and elite trends. Specifically, we find that: (1) ideological divergence between Democrats and Republicans has increased dramatically within each domain, just as it has in Congress; (2) economic, racial, and social liberalism have become highly correlated across state-party publics, just as they have across members of Congress; (3) ideological variation across state-party publics is now almost completely explained by party rather than state, closely tracking trends in the Senate; and (4) senators’ liberalism is strongly predicted by the liberalism of their state-party subconstituency, even controlling for their party affiliation and their state public’s overall liberalism. Taken together, this correspondence between elite and mass patterns suggests that members of Congress are actually quite in synch with their constituencies, if not with individual citizens.