After his 1946 re-election victory , Warren began planning a run for president in the 1948 election . The two front-runners for the nomination were Dewey and Robert Taft , but Warren , Harold Stassen , Arthur Vandenberg , and General 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
1948 Republican National Convention
1948 Republican National Convention
Earl Warren