Suffice it to say, it's really tough to interrogate reality when you have nothing but contrapositive indications and your response is "yes, this only applies to this one instance though".
This is why studying things systemically rather than through a collection of historical anecdotes you've picked up is a vastly superior system for modelling reality. This argumentum ad collection of ad hoc historical anecdotes that reify my pseudoscientific ideas is less interesting intellectually than Horoscopes.
We don't need to discuss this further as it is highly incendiary and you're not allowed to have arguments about topics that make people upset, so any polemicist is basically unchecked.
This article is a good introduction to the history of US drug enforcement: https://timeline.com/harry-anslinger-racist-war-on-drugs-pri...