On March 29, 1952 he surprised Democratic leaders by saying he would not seek re-election
He says 
he could have defeated his Democratic rival, former Congressman Nick... [DOC] [TLE] 1952 | Presidential Campaigns & Elections Reference [PAR] Adlai Stevenson, John Sparkman, Democratic 27,375,090 44.33% 89 16.8% ... 
unpopular President Harry S. Truman would not commit to seeking another term 
.... but pressure from Republican party leaders forced Eisenhower to omit it from 
.... March 29, 1952: Truman declares that he will not be a candidate for re-
election.