Story highlights Washington, D.C. voters approved a measure to legalize small amounts of marijuana for recreational use

Marijuana is still a restricted substance, according to the federal government, which is based in Washington, D.C.

Can legal pot follow the path of same-sex marriage to wider acceptance around the country?

Supporters hope so, in the wake of victorious marijuana legalization campaigns in Oregon, the District of Columbia, and, as appears likely, in Alaska.

The D.C. vote brings legal pot into the backyard of the federal government, which still classifies marijuana as one of the most dangerous substances -- on par with heroin.

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Attorney General Eric Holder told CNN recently that he's "cautiously optimistic" about the way Colorado and Washington state so far have handled their legal pot industries.

The Justice Department issued guidelines to federal prosecutors last year to focus their attention on eight priorities in marijuana enforcement, including stopping distribution of marijuana to minors, and blocking gangs and cartels from benefiting. The federal government still bans marijuana from federal property, including national parks, which takes up a significant chunk of the capital city.

A Justice Department spokesman said: "When we developed our department priorities over a year ago, we intended to set out a consistent enforcement approach that would be applicable across the country. As our Aug. 29, 2013 guidance memorandum laid out, the department's enforcement resources will continue to be aimed at the most significant threats to our communities. This approach relies on states instituting strict regulatory regimes to adequately protect public safety."

The D.C. law could take effect in March of 2015, if Congress doesn't find a way to step in to block it during a review period.

A Republican lawmaker from Maryland has vowed to try to block the DC law, but Sen. Rand Paul, who is in line for a powerful Senate post overseeing the District of Columbia, has said he opposes any congressional interference on the will of city voters.

"This victory is dedicated to everyone still sitting in jail tonight because of marijuana prohibition," Adam Eidinger, the Chair of the DC Cannabis Campaign, said in a statement. "District residents have made their voices heard loud and clear. The road to justice won't end on Capitol Hill."