McCarran Internal Security Act Passes Over Truman Veto, Requires Communist Registration

President Harry Truman vetoes the Internal Security Act of 1950 (McCarran Act) on September 22, 1950, sending Congress a lengthy veto message criticizing specific provisions as “the greatest danger to freedom of speech, press, and assembly since the Alien and Sedition Laws of 1798,” a “mockery of the Bill of Rights” and a “long step toward totalitarianism.” Truman states he takes this action only after the most serious study and reflection and after consultation with the security and intelligence agencies of the Government. The Department of Justice, Department of Defense, Central Intelligence Agency, and Department of State all advise him that the bill would seriously damage the security and intelligence operations for which they are responsible. In his veto message, Truman declares “In a free country, we punish men for the crimes they commit, but never for the opinions they have.”

Congress passes the McCarran Internal Security Act four months into the Korean War over Truman’s veto by large margins: 248 to 48 in the House and 57 to 10 in the Senate following a twenty-two hour continuous battle. Thirty-one Republicans and 26 Democrats vote in favor, while five members of each party oppose it. Democratic Senator Hubert Humphrey leads the outnumbered opposition in the Senate despite having voted in favor of the law the first time. The act, sponsored by Senator Pat McCarran (D-Nevada) after its principal sponsor, requires Communist organizations to register with the federal government. It creates a Subversive Activities Control Board (SACB), which on the petition of the attorney general can order an organization it determines to be Communist to register with the Justice Department and submit information concerning membership, finances, and activities. The act requires the Communist Party and 24 other organizations charged as Communist to register with the Justice Department, though none comply.

Senator Mundt tells a Senate hearing that the legislation is a response to what the House Un-American Activities Committee learned when investigating “the so-called pumpkin papers case, the espionage activities in the Chambers-Hiss case, the Bentley case, and others.” The House Un-American Activities Committee holds highly publicized hearings demanding witnesses name suspected Communists, leading to blacklists that destroy careers in Hollywood and beyond. This period, known as McCarthyism, creates immense pressure on lawmakers to prove they are “tough on Communism.” The 1964 decision in Aptheker v. Secretary of State rules unconstitutional Section 6, which prevents any member of a communist party from using or obtaining a passport. In 1965, the Court votes 8-0 in Albertson v. Subversive Activities Control Board to invalidate the Act’s requirement that members of the Communist Party register with the government, holding that the information party members are required to submit could form the basis of their prosecution, thereby violating their Fifth Amendment right against self-incrimination. Congress repeals the act in 1990, but the McCarran Act establishes the legal framework for political persecution and civil liberties restrictions that serves as a template for subsequent national security state overreach.