The Internal Security Act, or McCarran Act, of 1950 was a massive and complex conglomeration of varied security measures as well as many features of the MUNDTNIXON BILL and an Emergency Detention Bill, which had been introduced, unsuccessfully, earlier in 1950. Passed over President HARRY S. TRUMAN'S veto in September, shortly after the outbreak of hostilities in Korea, the measure went beyond the Truman loyalty program for government employees and attempted to limit the operation of subversive groups in all areas of American life. It also sought to shift the authority for security matters to congressional leadership.
The measure, the most severe since the SEDITION ACT of 1918, was composed of two parts. Title I, known as the Subversive Activities Control Act, required communist organizations to register with the attorney general and furnish complete membership lists and financial statements. Although membership and office holding in a communist organization was not, by the act, a crime, the measure did make it illegal knowingly to conspire to perform any act that would "substantially contribute" to the establishment of a totalitarian dictatorship in the United States. It also forbade employment of communists in defense plants and granting them passports. Finally it established a bipartisan SUBVERSIVE ACTIVITIES CONTROL BOARD to assist the attorney general in exposing subversive organizations. In ALBERTSON V. SUBVERSIVE ACTIVITIES CONTROL BOARD (1965), the Court held the compulsory registration provisions unconstitutional. (See MARCHETTI V. UNITED STATES, 1968.)
Title II provided that when the President declared an internal security emergency, the attorney general was to apprehend persons who were likely to engage in, or conspire with others to engage in, acts of espionage or sabotage and intern them "in such places of detention as may be prescribing by the Attorney General." Congress subsequently
authorized funds for special camps for such purposes. (See...