State laws prohibiting the possession of drugs is constitutional.
Federal laws prohibiting the possession of drugs is NOT constitutional.
That is why it took a constitutional amendment to prohibit alcohol. After the repeal of prohibition it was still constitutional for the states to prohibit it.
The supreme court informed congress that a federal law prohibition marijuana would not be constitutional. So they created the marijuana tax act to require the purchase of a government tax stamp to possess marijuana, then they refused to sell the stamps :-/
It eventually became a situation where the court just looked the other way while the federal government prohibited substance after substance.... that is how the war on drugs began.
And it’s only gotten worse. The drug war against cocaine and heroin led to the growth of use of crack and then to synthetic drugs like meth and fentanyl. Now a heroin addict can’t even get “well” on heroin unless it is spiked with fentanyl. Some pushers even intentionally overdose some of their “clients” because all the other junkies see the overdose and think “that guy’s got the best stuff”. It’s a cascade of unintended consequences and equal/opposite reactions.
Not to mention the violence. Few witnesses of the violence that Prohibition caused are alive to speak on it but we’re experiencing the same thing in all the major cities and spreading out to suburbs. People murdering each other for drug money, drug turf, and revenge/protection rackets etc.