One of the arguments of the legalization movement is (and has been) that it would kill the black cannabis market off
This has not happened at all, mainly due to slow regulation and high legal prices.
Many of the illegal growers cannot get legal, even if they want to, because of the high costs associated with legal cannabis.
Analysts of the cannabis industry in California, for instance, say that the easy part was to get people to vote for legalizing cannabis. The hard part does still remain, however- how to get the Californians to stop buying illegal cannabis and turn to the legal sector instead.