Douglas MacArthur each had significant support. Prior to the 1948 Republican National Convention, Warren attempted to position himself as a dark horse candidate who might emerge as a compromise nominee. However, Dewey won the nomination on the third ballot of the convention. Dewey once again asked Warren to serve as his running mate, and this time Warren agreed. Far ahead in the polls against President Harry S. Truman, the Democratic nominee, Dewey ran a cautious campaign that largely focused on platitudes rather than issues. Warren campaigned across the country on behalf of the ticket, but was frustrated by his inability to support specific policies. To the surprise of many observers, Truman won the election, and this became the only election Warren ever lost. After his 1950 re-election, Warren decided that he would seek the Republican nomination in the 1952 presidential election, and he announced his candidacy in November 1951. Taft also sought the nomination, but Dewey declined to make a third run for president. Dewey and his supporters instead conducted a long campaign to draft General Dwight D. Eisenhower as the Republican presidential nominee. Warren ran in three Republican presidential primaries, but won just a handful of delegates outside of his home state. In the California primary, he defeated a challenge from Thomas H. Werdel, whose conservative backers alleged that Warren had "abandoned Republicanism and embraced the objectives of the New Deal." After Eisenhower entered the race, Warren realized that his only hope of nomination was to emerge as a compromise nominee at the 1952 Republican National Convention after a deadlock between supporters of Eisenhower and Taft. After the primaries, Warren had the support of 80 delegates, while Eisenhower and Taft each had about 450 delegates. Though the California delegation was pledged to support Warren, many of the delegates personally favored Eisenhower or Taft. Unknown to Warren, Eisenhower supporters had promised Richard Nixon the vice presidency if he could swing the California delegation to Eisenhower. By the time of the convention, Nixon and his supporters had convinced most California delegates to switch their votes to Eisenhower after the first presidential ballot. Eisenhower won 595 votes on the first presidential ballot of the convention, just 9 short of the majority. Before the official end of the first ballot, several states shifted their votes to Eisenhower, giving him the nomination. Warren's decision to support a convention rule that unseated several contested delegations