In response to Chambers's accusations, Hiss protested his innocence and insisted on appearing before HUAC to clear himself. Testifying on August 5, 1948, he denied having ever been a Communist or having personally met Chambers. Under fire from President Truman and the press, the Committee was reluctant to proceed with its investigation against so eminent a man.  Committee member Richard Nixon , however, a Congressman from California, who later described Hiss's demeanor that day as, "insolent," "condescending," and "insulting in the extreme," wanted to press on.  Nixon had received secret information about the FBI's suspicions from John Francis Cronin , a Roman Catholic priest who had infiltrated labor unions in Baltimore during World War II to report on Communist activities and had been given access to FBI files.   Writing in a paper titled "The Problem Of American Communism In 1945," Cronin wrote, "In the State Department, the most influential Communist has been Alger Hiss."