A Tango Between Elite And Mass Politics

Party polarization, the ideological homogeneity within and the heterogeneity between the two parties in Congress has been the academic focus of American political science studies for decades. Nonetheless, explanations of its emergence remain incomplete. While extant literature have leveraged different party theories and time series studies to measure the impact of various electoral and institutional factors on congressional polarization, few studies have offer an integrated analysis of both dynamics and how the two mechanisms interact with each other to produce the synergetic effect on political polarization.To fill up this lacuna, we need to explore the electoral-institutional dynamics from a holistic perspective. The study focuses on polarization in the post-reform house from1973to2012. Throughout this time period, the House has undergone profound institutional reforms that alter the nature of party leadership and the agendas, rules and procedures of party members’voting behavior. And at the same time, the electoral bases of House members have also experienced a series of demographic changes that restructure party competition at the grass roots.In order to gauge the impact of these electoral and institutional changes in the last four decades on party polarization in the House, I leverage the spatial theories and dimensional analyses by dividing the measurement of polarization into two subsets: intraparty cohesiveness and interparty distance, quantifying both with first-dimension DW-NOMINATE scores. I then measure how much influence do electoral and institutional factors exert upon these two indicators with regression models. I find, generally speaking, both the electoral factors and institutional factors provide the dynamics for the growing interparty distance and the rising intraparty cohesiveness. Taken together, these two dynamics work as complementary pieces for explaining party polarization in the post-reform House.I conclude with the argument that to understand how these two dynamics interact with each other, we must assess the transmission of political messages between mass and elite polarization from both bottom-up and top-down perspectives. Only when the changes within the constituency interact with institutional changes in Congress through party institutions does the complete picture of party polarization come into clearer focus.