It was not the Mafia -- the Kennedys were building- and construction-tycoons and traditionally they have a strong union .. and this union of course is part of the Mafia -- or vice versa .. no Builder can survive if the Union-Mafia is against him .. so the Kennedys were protected by the powerful Builder-Mafia until John F. made his brother Robert minister of justice and ordered to "dry out the Mafia" .. no the Mafia did not kill him for this, they just quit protecting him so he could be assassinated by whoever had a reason .. and there were several .. but surely not the Mafia ! A strong guess are once more the masters of money and Wallstreet as Kennedy announced an important speech for the days after returning from Dallas - concerning the FED and a possible change ..