Polarization Lost: Exploring the Decline of Ideological Voting in Congress after the Gilded Age

We examine the decline in congressional polarization that occurred during the 1920s, as party differences narrowed relative to the high levels that characterized the turn of the twentieth century — a period that has, until recently, been regarded as the high-water mark of partisan polarization in American politics. We note two sets of findings. First, replacement seems to have driven depolarization to a larger extent than conversion, but with different patterns among Republicans and Democrats. Second, both qualitative and roll call evidence suggests that agricultural and tariff policies were key early areas of interparty cooperation, providing important opportunities for cross-party and cross-regional coalitions (like the Farm Bloc and the Progressive Coalition) to form before the Conservative Coalition emerged in the late-1930s.