Politics as partisan warfare: that is our world. Over the last generation, American democracy has had one defining attribute: extreme partisan polarization. We have not seen the intensity of political conflict and the radical separation between the two major political parties that characterizes our age since the late nineteenth century. Within Congress, the parties have become purer and purer distillations of themselves. The parties are now more internally unified, and more sharply differentiated from each other, than anytime over the last 100 years. Moreover, this polarization is not limited to those in office. Over the last generation, there has been adramatic ideological and partisan sorting of voters as well. A centerÂ in America’s governance institutions has all but disappeared.
This Article explores the causes of this polarization. Are the causes relatively contingent and short-term ones, so that it is possible to envision this structure of extreme partisan polarization changing, perhaps if certain institutional changes were made in the way American democracy and elections are designed? Or are the causes deep-rooted and structural ones, so that the appropriate conclusion is that this extreme partisan polarization is likely to be the ongoing structure of American politics and democracy for the coming years, regardless of any efforts that might be made to diminish this polarization? In particular, the article explores three potential causes of this polarization, which I label Persons, History, and Institutions.