At the height of the John Birch Society's activity in the 1960s, critics dismissed its members as a paranoid fringe. After all, "Birchers" believed that a vast communist conspiracy existed in America and posed an existential threat to Christianity, capitalism, and freedom. But as historian Matthew Dallek reveals, the Birch Society's extremism remade American conservatism. Most Birchers were white professionals who were radicalized as growing calls for racial and gender equality appeared to upend American life. Conservative leaders recognized that these affluent voters were needed to win elections, and for decades the GOP courted Birchers and their extremist successors. The far right steadily gained power, finally toppling the Republican establishment and electing Donald Trump.

Birchers is a deeply researched and indispensable new account of the rise of extremism in the United States.