“Kennedy had the good luck to govern at the time of peak power for America,” Sabato explains in a phone interview from his office at the University of Virginia. “It was a troubled time in terms of civil rights and some other issues, but, by and large, it was a happy time. Things were moving in the right direction, and then the assassination, it was kind of a rebaptism by blood. Kennedy became a secular saint,” especially to the Democratic base, which has celebrated Kennedy at every convention since 1960…

“I don’t think Democrats still represent Kennedy in policy terms,” Sabato says. “Stylistically, most of the prominent candidates have tried to be another JFK. But they’ve all failed, even Obama. Nobody is another JFK. Obama doesn’t even remember Kennedy. He was an infant while Kennedy was president, and he is the first president not to have a living memory of Kennedy, so it’s stylistic rather than substantive.”

For Democrats, Sabato says, that’s the real Kennedy curse. JFK lives on as their hero, but his family and memory have made debatable marks on the party’s successes, and, at times, contributed to its failures. And from Johnson to Obama, they’ve all had to grapple with it.