In 1948, Harry S. Truman and Alben W. Barkley were elected president and vice president of the United States, defeating Republican nominees Thomas E. Dewey and Earl Warren. Truman, a Democrat and vice president under Franklin D. Roosevelt, had ascended to the presidency upon Roosevelt's death in 1945. He announced his candidacy for election on March 8, 1948. Unchallenged by any major nominee in the Democratic primaries, he won almost all of them easily; however, many Democrats like James Roosevelt opposed his candidacy and urged former Chief of Staff of the United States Army Dwight D. Eisenhower to run instead.