Can municipalities get away with regulating medical marijuana?

With the Justice Department's announcement last week that it won't be prosecuting medical marijuana cases in states where the practice is legal, the feds loudly and officially passed the buck on the subject. That leaves it up to medical-marijuana states and their municipalities to determine just how to handle all that weed. And there's no other place in the country where the issue's more pressing than Colorado, where vague medical marijuana laws entombed in the constitution have led to a pot gold-rush of mammoth proportions, with hundreds of people a day applying for state marijuana IDs and dispensaries popping up in nearly every storefront imaginable.

Senator Chris Romer plans to introduce a bill in the next legislative session that could impose some new statewide regulations, but in the meantime local governments are taking matters into their own hands. Some cities have passed outright bans on dispensaries, as Greeley's city council did last week. Here in Denver, City Councilman Charlie Brown is considering rules that would regulate them in the city and maybe generate more tax revenue for municipal coffers.

But a major question remains: Are Colorado cities and towns actually allowed to regulate weed?

After all, Colorado's medical marijuana law stipulates that a state department must implement its provisions, and the legislature has long designated the Colorado Department of Public Health and Environment with the task. Therefore, as a Colorado Municipal League newsletter sent to cities and towns last July notes, "local government business regulations may be preempted" by the CDPHE.

Some civic boosters may point out that Colorado communities by law are home-rule municipalities, meaning their ordinances can supersede state law. But savvy marijuana activists could argue that home-rule status didn't seem to hold much water here in Denver a few years ago, when city voters decriminalized small amounts of pot. At that point, many city and law enforcement officials hemmed and hawed, explaining weed was still illegal under state and federal law.

Either way, it's an issue that will likely be sorted out in court. All it's going to take is one aggrieved dispensary owner who's lost out on his or her business in Greeley or one of the other cities, like Broomfield and Superior, that recently banned the business. A lawsuit will follow, leaving it up to a judge to determine who, exactly, gets to manage the state's pot biz. In the meantime, that business will keep growing -- and much, much faster than municipalities can hope to regulate it.