As regards Kennedy:
John F. Kennedy (*). Charisma aside, the Bay of Pigs with JFK shrinking from use of air cover was the most reckless gaffe in foreign policy history, which his exemplary Cuban Missile Crisis negotiation didn't erase, leading to humiliation with Khrushchev, face-saving Vietnam buildup to show "manhood." But tax cut of $10 billion, puny by today's standards, spurred prosperity and is cited today by GOP supply-siders (but some Republicans opposed it then as "the biggest gamble in history").