The Tea Party movement emerged on the American political scene in the spring of 2009, shortly after Rick Santelli’s now famous rant on CNBC regarding the Obama administration’s mortgage relief plans for homeowners, where he encouraged people to mobilize and start a new Tea Party. That April, tax day protests in scores of cities were staged by activists who now de¿ned themselves as supporters of the incipient Tea Party movement. The Tea Party represented a substantial challenge to the Obama administration, and more generally to mainstream politics. It also represented a challenge to analysts of social movements. In this book, we take up the second challenge.