Partisan Polarization in American Politics: A Background Paper

Acute partisan conflict arising from the ideological polarization of the national parties is now a dominant feature of American politics. The series of prominent showdowns over fiscal policy between Democratic president Barack Obama and the congressional Republicans that has followed the Republican takeover of the House in 2011 represent the tip of the iceberg. Partisan disputes over matters large and small, personnel as well as policy, occur almost daily. Polarized parties, combined with divided government, have made legislative gridlock the normal state of affairs in Washington, overcome only when dire necessity compels short-term compromises to stave off such disasters as default on the national debt or a government shutdown. Conflict and gridlock have damaged the public standing of everyone involved, for most Americans detest the partisan posturing, bickering, and stalemate that leave disputes unresolved and major problems unaddressed (Hibbing and Theiss-Morse 1995). Congress's popular ratings have reached all time lows, with an average of 80% of respondents disapproving of its performance in polls taken over the past two years; barely half of Americans approve of even their own party's members and leaders. (1) Barack Obama's ratings sag with every showdown, and he has become the most polarizing president on record. (2) In polls taken since 2011, an average of more than three-quarters of respondents said they were dissatisfied with the nation's direction; dissatisfaction reached a record 88% during the summer of that year when House Republicans tried to force massive spending cuts by refusing to raise the nation's debt ceiling, thereby threatening global economic turmoil, before finally backing down. (3) "Ridiculous," "disgusting," and "stupid" topped the list of one-word descriptions of the goings-on collected by the July 28-31, 2011, Pew survey. (4) Such reactions have done little, however, to curb Republican enthusiasm for games of chicken on the edge of the fiscal cliff. America's governing institutions are inherently prone to stalemate and, according to James Madison's famous account in Federalist 10, designedly so. The bicameral legislature, presidential veto, and separate electoral bases and calendars of representatives, senators, and presidents were intended to thwart simple majority rule, and they always have. The Senate's requirement of a supermajority of 60 votes to overcome filibusters on most types of legislation imposes yet another barrier to action. Thus when the parties are deeply divided and neither enjoys full control of the levers of government, acrimonious stalemate or unsatisfactory short-term fixes to avoid pending disaster become the order of the day. To consider what, if anything, might alter this state of affairs, it is useful to have a clear idea of how it came to be. My purpose here is to provide a variety of summary data documenting what has happened and why. The evidence, in my view, shows that elite polarization is firmly rooted in electoral politics and is therefore likely to remain until electoral configurations somehow change. To begin, I review some well-known data confirming that the current partisan and ideological polarization of the Congress is the extension of a long-term trend. I then review the electoral underpinnings of this trend, reviewing the evolution of individual and aggregate voting patterns and showing how their interaction with the electoral system has contributed to divided government and partisan intransigence. Finally, I consider various scenarios for electoral shifts that might reduce partisan conflict and break the stalemate. Partisan Polarization in Congress The systematic evidence documenting the increasing partisan polarization in Congress is familiar to all congressional scholars. Keith Poole and Howard Rosenthal (joined later by Nolan McCarty) have been tracing this trend since the early 1980s through their analysis of members' first-dimension DW-Nominate scores, which are based on all nonunanimous roll call votes taken during each Congress and serve to locate each member for each Congress on a liberal-conservative scale that ranges from -1. …