In this persuasive reappraisal of Truman's 1948 victory, Harold Gullan argues that it was neither the "greatest upset in American political history" (as popular mythology would have it) nor merely a successful extension of the coalition built by Franklin Roosevelt (as many historians contend). Aided by so many fortuitous circumstances, Gullan declares, Truman should have won by an even larger margin. Despite the near unanimous opinion of polls, pundits,...