So we know the Chicago Mafia helped JFK win Illinois and therefore beat Nixon in 1960. This is established fact.

There is a credible theory that it was the Chicago and Mafia and the CIA who plotted to kill JFK in 1963.

**What specific action did JFK take in the interim to motivate the Mafia to turn on him? **

I can think of several possible answers, but haven't researched JFK as deeply as many on here and I'd love to hear your well-reasoned opinions.