As described by Politico, the so-called "Big Marijuana" lobby is fighting against legalization, much to the chagrin of hippies (and free-market libertarians) everywhere:
Medical marijuana is a billion-dollar industry — legal in 18 states, including California, Nevada, Oregon and Maine — and like any entrenched business, it’s fighting to keep what it has and shut out competitors. Dispensary owners, trade associations and groups representing the industry are deeply concerned — and in some cases actively fighting — ballot initiatives and legislation that could wreck their business model.
That pits them against full legalization advocates, who have been hoping to play off wins at the ballot box last fall in Colorado and Washington state that established some of the most permissive pot laws in the world. Activists are hoping to pass full legalization measures in six more states by 2016.
From the point of view of dispensary owners, legalization laws — depending on how they’re written — can have little immediate upside and offer plenty of reasons for concern. For one, their businesses — still illegal under federal law — benefit from exclusive monopolies on the right to sell legal pot, but state measures still don’t end the risks of an FBI raid or Internal Revenue Service audit. Meanwhile, those same federal laws that prohibit growing, selling and using keep pot prices high.