• Decide to reschedule or deschedule marijuana as a schedule I narcotic.
Many of these options, of course, aren't very likely. Don't hold your breath waiting for the federal government to decriminalize marijuana anytime soon.
And all of them have some complications or challenges associated with them.
For one thing, the federal government has limited resources, and pursuing large criminal cases against distributors or growers is expensive.
If the feds want to crack down on distributors, it's far more likely they'll go less expensive routes, with things like civil forfeiture, says Robert Mikos, a law professor at Vanderbilt University who specializes in federalism and criminal law.
But even that has challenges.
"This drug is so ubiquitous, and there are so many sellers out there," says Professor Mikos. "Even if the federal government goes out and conducts raids against a dozen – which is a big undertaking – you might have hundreds or thousands left untouched." An unintended consequence of such action could be to simply undermine the work Colorado and Washington have done to regulate the businesses, instead driving sellers back underground and making it tougher to enforce whatever regulations they implement.
Still, all those non-criminal actions the feds could take to make like difficult for marijuana distributors "are things the federal government can do and has done with regard to medical marijuana," says Mikos.
In fact, the federal response to the numerous states that have allowed some form of medical marijuana use offers a window onto how confused and piecemeal the terrain can be.