A friend of mine grandfather was a union boss in Mass.
He was a member of the “family” and knew Joe Kennedy from the old days.
Contrary to popular belief, the Kennedys weren’t trying to take down the “family” they were trying to get complete control of the “family”.
Could a Kennedy attempt to dominate organized crime, as you state, be fitted into a context of ethnic warfare in organized crimes? Not all gangsters are Italian-American; the big cities had plenty of Irish and Jewish "wiseguys", not to mention blacks, Poles, Germans, Greeks, etc. In the South and Southwest, the gangsters were mostly of British Protestant background, e. g., Benny Binion and H.K. Beebe.