Cronin shared with Nixon his 1945 privately circulated paper "The Problem of American Communism in 1945",[59] with much information from the FBI's William C. Sullivan who by 1961 headed domestic intelligence under J. Edgar Hoover.[60]
By May 1948, Nixon had co-sponsored a "Mundt–Nixon Bill" to implement "a new approach to the complicated problem of internal communist subversion ... It provided for registration of all Communist Party members and required a statement of the source of all printed and broadcast material issued by organizations that were found to be Communist fronts."He served as floor manager for the Republican Party. On May 19, 1948, the bill passed the House by 319 to 58, but later it failed to pass the Senate.[61] The Nixon Library cites this bill's passage as Nixon's first significant victory in Congress.[62]
Nixon first gained national attention in August 1948, when his persistence as a HUAC member helped break the Alger Hiss spy case. While many doubted Whittaker Chambers's allegations that Hiss, a former State Department official, had been a Soviet spy, Nixon believed them to be true and pressed for the committee to continue its investigation. 