A Choice, Not an Echo: Polarization and the Transformation of the American Party System

This dissertation offers an intellectual and institutional history of party polarization and ideological realignment in the postwar United States. It treats the construction of an ideologically sorted party system as a political project carried out by conscious actors within and around the Democratic and Republican parties. The work of these activists, interest groups, and political elites helped to produce, by the last decades of the twentieth century, an unpredicted and still-continuing era of strong, polarized partisanship in American politics. In tracking their work, the dissertation also account for changing ideas about the party system over time, starting with an influential postwar scholarly doctrine that cast bipartisanship as a problem for which polarization would provide the solution.;National politics at mid-century involved high levels of bipartisanship in government given the presence of significant liberal and conservative factions within both parties; weak and federated party structures; and mass partisan attachments defined more by affective ties of tradition and communal affiliation than by issues and ideology. National politics at century's end involved levels of partisan discipline in Congress unseen since the Gilded Age; robust national party organizations; and an electorate that had followed political elites in sorting itself ideologically among the two parties. The movement from the first era to the second is the subject of this project, which argues that, during these decades, America's two-party system gained a programmatic cast and logic long considered alien to the country's political traditions. Long-term technological and demographic developments undergirded the rise to predominance of issue-driven party activism, while southern realignment provided a key electoral engine driving ideological sorting. But these processes took specific form through the work of activists and party elites, and they drive the dissertation's narrative.;The project contributes a historical narrative and context to the popular and scholarly discussion of contemporary party polarization, by identifying the origins of modern polarization in developments dating to the early postwar period and by historicizing Americans' longstanding debates over partisanship. By restoring parties as institutions to the forefront of an analysis of postwar political history, moreover, the project helps to recast key historiographic themes relating to the rise of the right and the decline of the New Deal order.