Studies of social movements and of political parties have usually treated them as separate and distinct. In fact they are deeply intertwined. Social movements often shape electoral competition and party policies; they can even give rise to new parties. At the same time, political parties and campaigns shape the opportunities, personnel, and outcomes of social movements. In many countries, electoral democracy itself is the outcome of social movement actions. This book examines the interaction of social movements and party politics since the 1950s, both in the United States and around the world. In studies of the US Civil Rights movement, the New Left, the Czechoslovak dissident movements, the Mexican struggle for democracy, and other episodes, this volume shows how party politics and social movements cannot be understood without appreciating their intimate relationship.