To the best of my knowledge, Sinatra came in contact with mob figures during his rise to stardom in the 1940s. The interesting political angle on this, of course, was Sinatra's ties to both Sam Giancana and JFK. Sinatra served as go-between when JFK was lining up a mafia hit-squad to use against Castro. Meanwhile, these very same gangsters were tied to Jimmy Hoffa and Howard Hughes. The epicenter for all this was Las Vegas, where the netherworld of showbusiness, politics and the trade union bureaucracy came together. This would make for an interesting movie, don't you think? With Johnnie Depp as Sinatra?
Louis Proyect
(http://www.panix.com/~lnp3/marxism.html)