I know POTUS is anti-drug, and he's old school, so he's probably still got that reefer madness mentality. Or he could be saving it for like Sept-Oct 2020 to maximize its effect on his support.
But I agree that there's lots he could do, but I imagine the little stuff(compared to pedos and maniacs with nukes) will take care of itself after the maniacs are neutralized.