I certainly wouldn't be surprised. There's black markets for just about anything. Why wouldn't one continue in a market that has been entirely that way for quite some time?
You think drug dealers are gonna suddenly want to give up a percentage of their money to Uncle Sam? They've already shown they don't give **** about following the law...
Yeah, black market booze is really popular these days. Budweiser has a hell of a time fighting guys in their garages home brewing.
Who cares if drug dealers don't want it. Drug dealers have it made now because the economic system is entirely to their advantage. Take away the advantage and they can wish for whatever they want but the reality is they won't get it.
Take pot for example. As of now the current black market price is roughly $300 an ounce. For comparison, the most expensive food I can think of that's grown are white truffles, which sell at a high end for $2,000 a pound, or $125 an ounce. Now the reason truffles are expensive is pretty simple. They are a pain in the *** to grow and to find them in the wild you need like a pig or a dog or something.
But pot? It's not like it's some sort of rare plant. Or that it's difficult to grow. While it's not quite as simple as just throwing a seed out to get high quality (not just in terms of potency, but in appearance and other qualities) stuff it's simple enough to grow to the point that the average person who grows tomatoes in their backyard can accomplish it. The reason it's so expensive is that the average joe won't risk to grow it, as growing any amount is a felony offense in most states. So only those willing to break the law grow the stuff and artificially restrict the supply. The demand is still there, and as simple economics and logic tell us "reduced supply + increased demand = inflated price."
So all of a sudden pot becomes legal. Now instead of clandestine houses and fields in the middle of National Forests and other places there can be hundreds of thousands of acres of greenhouses and warehouses devoted to growing the stuff. All of a sudden supply vastly increases and the producers fight with each other to sell it until some baseline price is established, which will be well below $300 an ounce. Probably more like $50 an ounce. Now the drug dealer has an interesting proposition. Does he still continue to grow pot and sell it for a price that undercuts that one? If he does he's still risking some legal consequences. Even if I homebrew or grow my own tobacco I just can't go out and sell it to the public, that requires licensing and stuff. So If the dealer has to sell their stuff at even $45 an ounce but also has to factor in the cost of growing it, and let's say some sort of minimal cost of $5 an ounce, that's a net profit of $40 an ounce. So to make $4,000 the dealer would have to sell 100 ounces, or a little over 6 pounds. That's a lot of product to move, especially in an environment where the regular user would just rather go to the store and pick different varieties and not worry about buying from someone unlicensed.