As of Monday, marijuana is legal in the state of Colorado. Governor John Hickenlooper has signed an official proclamation making Amendment 64, the voter-passed amendment that legalizes possession of up to an ounce of marijuana, part of the state’s Constitution.

That sets up a confrontation between the state and the federal government, given that marijuana possession is still a federal crime.

In theory, the Drug Enforcement Agency could try to arrest everyone buying and selling pot in Colorado and Washington, which also legalized the substance last month. But in practice, there just aren’t enough DEA agents to staff an operation of that scale. It would be, in the words of UCLA drug policy expert Mark Kleiman, “an exercise in shoveling sand against the tide.” So a likelier outcome, as Sarah Kliff has reported, is that the federal government will take a lighter touch. Some dispensaries might get busted up, but the drug would be left alone.

- Read the entire article at  The Washington Post .