Given the absurd disconnect between US law and anything resembling ethics, I doubt this is true. If you're on the left, you're as likely to see law enforcement as bad people, and if you're on the right, substitute guns for marijuana and you're likely to have very different views. While some people might think this way at a surface level, I suspect the number of people who base their view of morality on laws is vanishingly small compared to the number of people who base their view of laws on their morality.
> Banning something where the rest of the culture is trying to normalize it probably is futile.
Good thing there's no cultural movement to normalize the substance we're talking about.
> It's hard to ignore that marijuana seems to be much more prevalent now that it's been legalized in many places.
Hard to ignore, but easy to explain with explanations other than "it made things worse". Does it occur to you that maybe people just aren't hiding their use now that it's legal?