Uh, yeah. There will be a black market. But it will be interfering with official monopolies that are owned by "people we know". Do you not think that they are capable of finding grow ops? The black market thrived because it it had support from the people who knew that marijuana was not a Schedule 1 drug. For the most part, law enforcement had gotten off it's back. You want to see action? Fuck with the 1%'s livelihood and you will see it. Them bitches may not put you in jail but they will go after everything you own with lawyers. How do you think they got rich and stayed that way?
Look, here is an article about the money behind Ohio's proposed medical maryjane program...
http://www.cincinnati.com/story/news/2015/03/25/tafts-support-responsibleohio-marijuana-legalization-measure/70442178/
The attempt failed, but they tried to give a monopoly of cannabis production in Ohio to the immortal and conservative money and associated descendants of US President Robert Taft. "Because these are people we know - they'll do a great job. We searched high and low for the best people to do this - and the Taft family is it. We know them... not one cent will reach the Mexican cartels" Sorry, I slipped into TRUMP!ese.
I am on record for loathing Hillary for many reasons. But this is when you have to hold your nose and pick the lesser of two evils. Your comment about true Republicans and small government is laughable. History does not bear it out. They say that, I agree. But I think a true Republican these days is about limiting education in order to keep people gullible enough to buy their crap about "personal liberty". They have spent like fucking mad for no reason other than to pay people off for the last 40 years - and guess what my friend? They are coming for the scraps they left behind that you intend to live on.