After winning election to the Senate in 1938 over incumbent Democrat Robert J. Bulkley , Taft repeatedly sought the Republican presidential nomination , often battling for control of the party with the moderate faction of Republicans led by Thomas E. Dewey . He also emerged as a prominent non-interventionist and opposed U.S. involvement into World War II prior to the 1941 Japanese Attack on Pearl Harbor . Taft 's non-interventionist stances damaged his 1940 candidacy , and the 1940 Republican National Convention nominated Wendell Willkie . Taft sought the presidency again in 1948 , but he lost to Dewey at the 1948 Republican National Convention . He opposed the creation of NATO and criticized President Harry Truman 's handling of the Korean War
1940 Republican National Convention
1940 Republican National Convention
Robert A. Taft