The roots of the anti-communist network of the 1940s and 50s date back to the Red Scare of 1919-20. It was maintained for the next two decades by elements within the American Legion and the Chamber of Commerce and expanded its appeal during the labor struggles of the late 30s. This led to the creation in 1938 of the House Un-American Activities Committee (HUAC), which attracted conservatives and anti-New Dealers of both parties. In 1940, the Smith Act made it illegal to “teach or advocate” the overthrow of the government or belong to any organization that did.

Meanwhile, the emerging network was attracting some conservative union leaders, Catholic activists who undertook to drive the communists out of the labor movement, a significant number of disillusioned ex-communists, and liberals who turned against the communists after the Hitler-Stalin pact. That was when fascists and communists ceased to be seen as opposites and were both identified as expressions of totalitarianism.

By the 1940s, all these elements had come together in a tightly interconnected network. The hostility towards communism would fade for a time when the United States and the Soviet Union were wartime allies, but it would return strongly after the war and have a major influence on the development of McCarthyism.

According to Ellen Schrecker’s, The Age of McCarthyism, the appeal of anti-communism in the 1940s and 50s can be ascribed to a combination of the traditional American fear of “subversives” — including foreigners, minorities, and dissidents — with anxiety over the modern, secular, post-war world. She identifies the two most important interest groups in the anti-communist network — along with right-wing politicians — as (1) anti-union business owners looking to blame workers’ legitimate grievances on outside agitators and (2) law enforcement, private detectives, the FBI, and military intelligence, which typically combined an authoritarian mindset with a history of fighting radicalism and labor unrest.

(It should be apparent that the Republican attempt to revive anti-communism as a campaign issue as of 2026 draws on all these same elements.)