The presidential election of 1948 has rightly become a textbook case of malpractice by political pollsters. That year, the policies of the Truman administration split the old Roosevelt Coalition — and with it, the Democratic Party — three ways: Desegregation of the armed forces drove the Dixiecrats to nominate Strom Thurmond; confrontation with the Communists drove the Progressives to run former vice president Henry Wallace; and Truman headed the rump of the party.
The pollsters predicted a narrow win for Republican Thomas Dewey. They were wrong.
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