they mean the heavy criminalization of drugs wasnt about drugs, it was about opressing people. Nixon had a problem with counter culture hippies and blacks. The solution was to impose heavy criminal charges for what they did, smoking pot and also herion in the black communities at the time (so I’ve read several times, I’m no historian nor expert though).

Like if you wanted to oppress middle class white people you could make chardonnay illegial and jail prople who you send the cops to bust for drinking it