Gotti would be turning over in his grave if he read your post, Mick!
Yes, indeed: RICO was one of two body-blows to the Mafia. The other was drugs. Contrary to their own myth-making, the Mob had always been involved in drugs. But, as long as the drug traffic was largely confined to blacks, Hispanics and other groups that society didn't care much about, the authorities usually looked the other way. In the Sixties, drug use exploded among white middle-class youngsters--many of whom were children of cops, politicians, judges, etc. That's when the authorities here started cracking down on the drug rackets and handing down big sentences. Facing big sentences, Mob guys started breaking omerta and implicating higher-ups. Don Corleone was prescient when he predicted that drugs would be the ruination of the Mafia.