Troubled by the repression unleashed by World War I, Justice Oliver Wendell Holmes, Jr. insisted that the functioning of the democratic system depended on the right of all Americans to be heard, regardless of how obnoxious their views, provided their words posed no "clear and present danger." This ideal, which became a defining aspect of the nation's political culture in the generation following the war, was put to the test during World War II by the "un-American" rhetoric of Communists, Bundists, Christian fundamentalists, Black nationalists, and others. Idealism faltered as private citizens and government officials, including erstwhile civil libertarians, demanded a new, "realistic" definition of free speech. This book tells how FDR's three attorneys general and their staffs struggled to adjust and apply the Holmesian ideal in the face of demands from the president and the public for ideological conformity and total security. It examines how the ideal postulated by Holmes and generally accepted by liberals and intellectuals in the interwar period fared during its first real test in the conflict widely known as the "good war."