In 1944 , Roosevelt appointed Hannegan , who had been the Collector of Internal Revenue in St. Louis , to the DNC after testing him by asking for his help with his income tax return . As Democratic chairman , Hannegan was responsible for brokering the deal that made Truman Roosevelt 's running mate that year . Shortly before the 1944 Democratic National Convention , Roosevelt famously sent Hannegan a letter stating he would be " happy to run with " either Truman or Supreme Court Justice William O. Douglas . Vice President Henry A. Wallace nearly won the nomination , but Hannegan worked feverishly to secure Truman 's nomination . Hannegan later joked he wanted his tombstone inscribed with the words " Here lies the man who stopped Henry Wallace from becoming President of the United States . " Though plagued with ill health for much of his tenure as party chairman , Hannegan emphasized voter turnout efforts in Roosevelt 's 1944 re-election campaign and prevented an upset by Thomas Dewey , who won a surprising 46 percent of the popular vote that year . He promoted a liberal policy agenda for the national party and was a strong advocate of labor unions . Hannegan stepped down as chairman after Democrats suffered Congressional losses in the 1946 , the midterm elections , but his ideological focus at the helm of the party contributed to Truman 's upset win in the Presidential election of 1948 , and influenced his Fair Deal proposals
1944 Democratic National Convention
1944 Democratic National Convention
Robert E. Hannegan