Regardless of whether one accepts the individual-liberty case for legalizing marijuana, the consequentialist case is convincing. That is because the history of marijuana prohibition is a catalogue of unprofitable tradeoffs: billions in enforcement costs, and hundreds of thousands of arrests each year, in a fruitless attempt to control a mostly benign drug the use of which remains widespread despite our energetic attempts at prohibition. We make a lot of criminals while preventing very little crime, and do a great deal of harm in the course of trying to prevent an activity that presents little if any harm in and of itself.
Of course I find the consequentialist case attractive, for the simple reason that it is a rational case. That said, though, the individual-liberty case trumps all for me.
The US government simply has no constitutional power to ban substances like marijuana absent a constitutional amendment permitting it to do so.
We understood that once upon a time. But progressives – who had to settle for just such an amendment to prohibit booze, finally figured out a way to end-run the constitution and impose their insane infringements on individual liberty by simply agreeing to ignore our founding documents – for our own good, of course.