JFK The Worst President of the 20th Century?

Not unless they manage to expunge Jimmuh Carter from the history books, but one historian thinks JFK was simply awful as president:

As I studied the Vietnam war over the last 14 months, I began to think that John F. Kennedy probably was the worst American president of the previous century.

In retrospect, he spent his 35 months in the White House stumbling from crisis to fiasco. He came into office and okayed the Bay of Pigs invasion. Then he went to a Vienna summit conference and got his clock cleaned by Khrushchev. That led to, among other things, the Cuban missile crisis and a whiff of nuclear apocalypse.

Looming over it all is the American descent into Vietnam. The assassination of Vietnam's President Diem on Kennedy's watch may have been one of the two biggest mistakes of the war there. (The other was the decision to wage a war of attrition on the unexamined assumption that Hanoi would buckle under the pain.) I don't buy the theory promulgated by Robert McNamara and others that Kennedy would have kept U.S. troops out. Sure, Kennedy wanted out of Vietnam -- just like Lyndon Johnson wanted out a few years later: We'll scale down our presence after victory is secure.

There's more at the link.

I don't think you can dispute the fact that Kennedy's legacy, and especially the whole Camelot image that was created after his death, has been enhanced by the fact he was assassinated at such a young age. In the minds of many Americans he will forever be the tanned, young, seemingly healthy and smiling 46-year old with the fashion plate wife and cute young kids, and therefore his record in office won't really matter.

However, had he lived he probably would have faced a tough election in '64 and assuming he would have won, Vietnam would have been his mess and not LBJ's.  His health may have become an increasing problem, and his dalliances with various females other than his wife might not have stayed secret.  The upheavals of the 60's still would have gone on and Kennedy might not have done any better job in dealing with them than did LBJ.

But we'll never know.