One fact that hasn't been mentioned is that Denver is a consolidated county/city, meaning it is governed by a charter. As such, they can enact laws by ordinance that are more strict than state laws. If the ordinance passes and enough of you petition it, it can be forced onto the ballot for a popular vote. Charter, or home rule communities are given greater leeway in crafting ordinances than statutory communities. IIRC, GratefulMeds and others tried to get Nederland to go home rule because it would give the town greater control over MMJ regulations. The Denver ordinance shows the other side of home rule. FWIW, I still think all Colorado communities should be governed by charter.