In the aftermath of the 2016 presidential election, fewer themes have received more attention from scholars and public commentators than political polarization. However, given the recent focus on tension and conflict in contemporary American society, the present also seems an especially appropriate moment to investigate those fundamental structures that have successfully worked in the opposite direction to bind and stabilize the American polity. The goal of this paper is precisely this task, and to emphasize the centrality of one particular structure that has played such a stabilizing function: the political parties. Parties are often invoked in discussions of political polarization. However, I focus on the significant role of political par...