It's always seemed like conservatives are just as into weed as liberals, they just don't want "those people" to have it. The asshole conservatives in my family that say we should stop oppressing responsible gun owners while firing their AK with five beers in them have been growing and smoking since the 70s, and it regularly polls pretty highly in conservative demographics. It's just the politicians ignoring that and niches of diehard cop groups that refuse to accept that 90% of the stuff they pushed during dare were lies and that nobody should trust them.