Not sure why you're being downvoted as I think the empiric evidence supports the position that drug laws (and many others) are selectively enforced on the basis of socioeconomic status and race.
Cocaine is a schedule 3 stuff. Cannabis and crack cocaine are schedule 1.
As further suggestive evidence of this, watch the correlation between donors/friends of those same old white guys entering the MJ business, and the rapid "evolution" of the willingness to switch stances on legality.
You can even evaluate this without malice: Some say MJ is dangerous, and some say it's great. The status quo is that it is banned. Changing that creates the risk that it is bad and the change will be blamed on you, but legalizing will not bring you much glory, so you support the status quo until you have sufficient incentive (most likely $$$, but a strong push from the public instead of "meh" would also count).
That said, I find a mix of opportunism and greed to be the most likely explanation.
Further support is the fact that most politicians support punitive action against people with drug possession charges, rather than mandating treatment. There's solid evidence that drug crisis can be solved in the long term by access to treatment, and more evidence that punitive measures increase crime and continue the poverty cycle.
The only reason to support the current drug laws is literally because you want more crime and drug use.
Cocaine is a schedule 3 stuff. Cannabis and crack cocaine are schedule 1.