He placed the once-autonomous districts under centralized receivership, packed the union bureaucracy with men directly beholden to him, and used UMWA conventions and publications to discredit his critics. The fight was bitter but Lewis used armed force, red-baiting, and ballot-box stuffing and, in 1928, expelled the leftists. As Hudson (1952) shows, they started a separate union, the National Miners' Union. In Southern Illinois, amidst widespread violence, the Progressive Mine Workers of America challenged Lewis but were beaten back. After 1935, Lewis invited the radical organizers to work for his CIO organizing drives, and they soon gained powerful positions in CIO unions, including auto workers and electrical workers.