David Corn is a veteran Washington journalist and political commentator. He is the Washington bureau chief for Mother Jones magazine and an analyst for MSNBC. He is also the author or coauthor of four New York Times bestsellers, including the #1 bestseller Russian Roulette, Showdown, and Hubris; and the author of the novel Deep Background. His new book, American Psychosis: A Historical Investigation of How the Republican Party Went Crazy, argues that since the 1950s the GOP has encouraged and exploited extremism to gain power.