In the conclusion of their history of radical-right politics in the United States, The Politics of Unreason, Seymour Martin Lipset and Earl Raab described American parties as the “chief practical bulwark” against extremists. They were correct. But Lipset and Raab published their book in 1970, just as the parties were embarking on the most dramatic reform of their nomination systems in well over a century. Everything was about to change, with consequences far beyond what anyone might have imagined.
