Identifying varied interest groups such as business tycoons, Christian denominations, and Southern Democrats, Goodall demonstrates how countersubversive politics was far from unified: groups often pursued clashing aims while struggling to balance the competing pulls of loyalty to the nation and liberty of thought, speech, and action. Meanwhile, the federal government pursued its own course, which alternately converged with and diverged from the paths followed by private organizations. By the end of World War II, alliances on the left and right had largely consolidated into the form they would keep during the Cold War. Anticommunists on the right worked to rein in the supposedly dictatorial ambitions of the Roosevelt administration, while New Deal liberals divided into several camps: the Popular Front, civil liberties activists, and embryonic Cold Warriors who struggled with how to respond to communist espionage in Washington and communist influence in politics more broadly.

Rigorous in its scholarship yet accessible to a wide audience, Goodall's masterful study shows how opposition to radicalism became a defining ideological question of American life.