How did Barack Obama, a “center-left pragmatic reformer” advocating “a moderately activist government constrained by a sense of trade-offs” polarize the public and the Congress so quickly and so thoroughly during his first 18 months in office? First, Americans were polarized from the...

Using the 2010 Cooperative Congressional Election Study, which provides both a very large national sample of voters and a rich array of questions regarding political attitudes, behaviors, and beliefs, I investigate the Tea Party movement’s role in the Republican midterm victory. I find that...

I trace out the etiology of partisan polarization of the House and Senate since the 1970s through an examination of exogenous and endogenous sources of trends in members' DW-Nominate and adjusted ADA Scores. I find that the increase in polarization is strongly related to the growing differences...