Here from vox.com are two objections to marijuana retail monopoly that don’t hold up, in my opinion:
“For states to establish a monopoly on marijuana production and sales, voters or elected officials would have to approve laws that essentially give state governments control over the marijuana industry. Even if a majority of Americans support legalizing marijuana, it’s unclear whether they would support turning their state into a pot dealer — and even if they did, state governments might be reluctant to do this, since it would mean forcing state employees to violate federal law . . . ” That’s from http://www.vox.com/2015/4/27/8500531/marijuana-legalization-commercialization-prohibition.
First, voters in some states might like monopoly: A poll I did among North Carolina voters in 2013 showed a clear preference for state stores (58 percent), our model for liquor, over private stores (19 percent), with 23 percent undecided. https://newtax.files.wordpress.com/2013/03/nc-marijuana-polling-march-2013.pdf, page 2.
Second, in the face of federal law, North Bonneville, Washington, is already selling marijuana via a quasi-monopoly, a Public Authority of the kind described in Chapter 4 of the RAND Report. See http://www.washingtonpost.com/business/economy/a-local-government-in-wash-state-tries-to-corner-the-market-on-marijuana/2015/03/16/fccb8216-c9b7-11e4-b2a1-bed1aaea2816_story.html. No arrests yet.
Not only a retail monopoly, of the kind that 17 states have for liquor, seems plausible. Production monopoly offers a lot of control; Louisiana is considering having LSU do the growing, as mentioned in a later post.