One thing Sawzaw said, I largely agreed with - "Are those violent gangs going to become church goers when the demand for their product goes away by legalization? They will switch to something worse like kidnapping."

Those kind of people will always diversify - when Prohibition ended,they didn't even need to break step - protection rackets, prostitution, kidnapping, even politics, anything where there is easy money to be made, including legal activities with a twist, such as property development with violence to move things along. After all, they are business - the boundary between legitimate and criminal activity is paper thin at times, and moves around.

But the implication that it's a good idea to tame the villains by giving them the pusher franchise, by keeping pot illegal, as a way of keeping them off doing worse stuff, doesn't really convince. In fact, if anything, this is one of the factors that it makes it easier for them to extend into other profitable areas, as already happens. And as happened during Prohibition, where bootlegging was just the jumping-off ground for organised crime.