Wallace served as Secretary of Agriculture under Roosevelt from 1933 to 1940. He strongly supported Roosevelt's New Deal and presided over a major shift in federal agricultural policy, implementing measures designed to curtail agricultural surpluses and ameliorate rural poverty. Overcoming strong opposition from conservative party leaders, Wallace was nominated for Vice President at the 1940 Democratic National Convention. The Democratic ticket of Roosevelt and Wallace won the 1940 presidential election, and Wallace continued to play an important role in the Roosevelt administration before and during World War II. At the 1944 Democratic National Convention, conservative party leaders defeated Wallace's bid for renomination, replacing him on the Democratic ticket with Harry S. Truman. The ticket of Roosevelt and Truman won the 1944 presidential election, and in early 1945 Roosevelt appointed Wallace as Secretary of Commerce.