 Barkley took an active role in the Truman administration, acting as its primary spokesman, especially after the Korean War necessitated the majority of Truman's attention.When Truman announced that he would not seek re-election in 1952, Barkley began organizing a presidential campaign, but labor leaders refused to endorse his candidacy because of his age, and he withdrew from the race.He retired but was coaxed back into public life, defeating incumbent Republican Senator John Sherman Cooper in 1954.