That's very interesting, but corrupt city machines don't gain revenue from liquor licenses if all licenses or consumption of any kind are banned

Where do you think you buy employment as a policeman?

do you have any reason to believe the nation-wide movement to push through an entire Constitutional amendment, which succeeded in 46 of the 48 states, was even slightly assisted by the interest of would-be corrupt policemen?

I suspect it was mostly pushed by identity voters who didn't know how things would turn out, but I imagine that the eyes of clever gangsters and corrupt policemen all lit up when they heard about it. I suspect that they put little effort into opposing it, which could count as assistance. If any of them did support it, I imagine it was as secretly as they could manage, and thus it might be difficult for us to know about even now.