It likely was a motive, but it doesn't necessarily make the quote real. I have trouble believing Nixon or his advisors would give a supervillain monologue like that, personally, even if those were their exact intentions.
read the whole thread man. I don't think anyone here doubts that drug enforcement in America is racially motivated, but you're the third person to cite that very dubious quote.
>Nixon advisor: We created the war on drugs to “criminalize” black people and the anti-war left
so it was more their political enemies in general rather than a race. Not to say it wasn't part racist.