A long-standing debate in American politics is about the proper structure for political parties and the relative power that should be afforded to party professionals versus issue activists. In this book, Byron E. Shafer and Regina L. Wagner draw systematically on new data and indexes to evaluate the extent to which party structure changed from the 1950s on, and what the consequences have been for policy responsiveness, democratic representation, and party alignment across different issue domains. They argue that the reputed triumph of volunteer parties since the 1970s has been less comprehensive than the orthodox narrative assumes, but that the balance of power did shift, with unintended and sometimes perverse consequences. In the process of evaluating its central questions, this book gives an account of how partisan alignments evolved with newly empowered issue activists and major post-war developments from the civil rights movement to the culture wars.