Internal Security Act

US legislation passed in 1950 by Congress over the president's veto (amended 1951, 1952, and 1954). It restricted the civil rights of communists in the USA and barred anyone who had ever been a member of a ‘totalitarian party’ from entering the country.

The act was passed in the political climate of the witch-hunts of the right-wing senator Joe McCarthy. It had already been made illegal 1940 to be a member of an organization advocating the overthrow of the government by force, and Communist Party leaders had been jailed on that ground.

The Internal Security Act consisted of two parts: Part I, the Subversive Activities Control Act, and Part II, the Emergency Detention Act. Part I classified communist organizations, created the Subversive Activities Control Board to identify such organizations, dealt with conspiracy and the transmission of secrets to foreign agents, broadened espionage and sabotage laws, and required the registration of foreign agents. Part II stipulated that the president might proclaim an internal security emergency in the event of the invasion of the USA, or any of its possessions, declaration of war by Congress, or insurrection within the USA in aid of a foreign enemy; it also provided for the detention of persons suspected of conspiracy for espionage or sabotage. The US Supreme Court ruled in 1965 that the section of the act requiring members of the Communist Party to register with the Department of Justice was unconstitutional because it violated the individual's protection under the Fifth Amendment against self-incrimination. Other parts of the act have also been subjected to serious legal and congressional amendment.