 The Select Committee 's chair was Senator John L. McClellan , and the vice chair was Senator Irving Ives . An equal number of Democrats and Republicans sat on the committee . Republican Senator Joseph McCarthy died on May 2 , 1957 , and was replaced by Republican Senator Homer E. Capehart . Democratic Senator Patrick McNamara resigned from the committee on March 31 , 1958 , to protest the Select Committee 's rough treatment of union witnesses . He was replaced by Democratic Senator Frank Church . 
