“When young, wealthy, and conservative John Fitzgerald Kennedy announced for Congress, many people wondered why,” it began. “Hardly a liberal even by his own standards, Kennedy is mainly concerned by what appears to him as the coming struggle between collectivism and capitalism. In speech after speech he charges his audience ‘to battle for the old ideas with the same enthusiasm that people have for new ideas.’ ”

He hadn’t changed his political stripes by the time he ran for the Senate in 1952, challenging incumbent Henry Cabot Lodge Jr. Stoll notes that Massachusetts newspapers wanting to back a liberal in that race came out for the Republican — the Berkshire Eagle, for example, endorsed Lodge as “an invaluable voice for liberalism.” When his reelection in 1958 made it clear that Kennedy would be running for the Democratic presidential nomination, Eleanor Roosevelt was asked in a TV interview whom she would support if forced to choose “between a conservative Democrat like Kennedy and a liberal Republican [like] Rockefeller.” FDR’s widow, then as now a progressive icon, answered that she would do all she could to make sure Kennedy wouldn’t be the party’s nominee.

Many on the left felt that way about JFK. When he decided to resume nuclear testing in 1962, Bertrand Russell attacked him as “much more wicked than Hitler,” and Linus Pauling, who would receive that year’s Nobel Peace Prize, predicted that he would “go down in history as . . . one of the greatest enemies of the human race.” Left-wing intellectuals raged against Kennedy’s failed attempt to topple Fidel Castro (the renowned sociologist C. Wright Mills said the administration had “returned us to barbarism”). Liberals within the administration expressed dismay for Kennedy’s unwavering support for tax cuts. Schlesinger called one of Kennedy’s exhortations “the worst speech the president had ever given.”