I don't think that there will be an explosion either. But my belief is in the main due to the fact that there are already quite a few people growing their own. I do feel that there will be a marked increase of personal (recreational) cannabis grows - and if that increase is coupled with a substantial percentage of the current growers deciding to "come out of the closet", it might appear to be an explosion.
I know it wouldn't be a deal-stopper, but it would be bad PR (IMHO) for a local government to deny itself the potential tax revenues from Prop19 because it wishes to prohibit things and then to turn around and attempt to get them by hitting the people that Prop19 gives a right to which those local governments are unable to prohibit. I'm sure there would be plenty of people who would be happy to help give maximum publicity if such a thing happened.
A lot depends on the attitudes of the majority (of voters) in the jurisdictions of those local governments. Decisions/actions that go against the wishes of the majority can often be fought after the fact by voting the people who made the decisions - or the people who appointed the people who made the decisions - out of their office. Unfortunately, it doesn't always work out that way because the voting public often seems to have a rather short memory. But that wouldn't be the fault of Proposition 19 or any other piece of legislation.
