Abstract: The Tea Party reached its peak during the 2010 midterm elections and helped propel Republicans into the House of Representatives. While commentary has focused on the Republican Party’s shift to the right in response to the Tea Party movement, this paper examines the Tea Party’s influence on the Democratic Party. Using Washington Post data on party voting, I find that Democrats who beat Tea Party candidates in competitive races are 6.5 percent more likely to vote with the Democratic Party in the congressional session following the 2010 midterm election. This brings the likelihood of voting with the Party up to 89.4 percent on any given vote, compared to the baseline of 82.9 percent. Possible explanations for this Tea Party effect a...