Mafia has been dealing drugs since Day One. Don Vito Cascio Ferro, the Sicilian pezzanovante, spent several years early in the last century in NYC, shaping up the loose Mafia scene into what became the Five Families, and setting up the first of many drug pipelines between Europe and North America. The Mob has always been well-positioned to deal drugs. They have the international connections, the feet-on-the-street to move it, and the brothels, bars, betting parlors, etc., to distribute it.

Until the Sixties, drugs was a small but profitable part of every family's income. Yes, most of their income came from gambling, etc., but the drug profits were too good to pass up. As long as the traffic was confined to racial minorities, jazz musicians and others that society didn't care about, the law was pleased to look the other way in return for bribes. But the drug explosion of the Sixties ruined many white, middle-class youngsters--including children of cops, judges, politicians, etc. Suddenly the penalties became big, and omerta was threatened.

The bosses had a dilemma: a soldier given a double-digit sentence might talk and endanger higher-ups. But Mafia is a pyramid scheme: a part of every soldier's or associate's take is kicked upstairs, eventually reaching the Don. If the Don decreed and enforced a ban on drugs, he'd just drive the traffic--and his own take--underground.

So the Dons came up with a typical Mafia hypocrisy: they decreed death for anyone caught dealing drugs. If a guy was nailed dealing drugs, they'd kill him before he had a chance to testify. But if he wasn't caught...well, what you don't know won't hurt you--as long as the money kept coming in. That decree had a kind of Darwinian effect: it scared off the weaker guys, leaving drug trafficking to the more resourceful guys who were less likely to get caught.