Democratic Mayor Vincent Gray signed a bill in March that decriminalizes possession of small amounts of pot. Under the law, set to take effect next month, possession of less than one ounce would become a civil offense subject to a $25 fine, one of the lowest in the nation.
District of Columbia leaders had been optimistic that Congress would not intervene, given that more than a third of the states have some form of decriminalization and federal officials appeared much more concerned about Colorado and Washington state, which have legalized the drug.
But on Wednesday, tea party-affiliated GOP Rep. Andy Harris of Maryland called the $25 fines too low and said the law would lead to a spike in drug use among young people. Harris, a physician, said marijuana has been shown to harm the developing brain.
"Whether you're 12 or 40, the fine is $25. In fact, if you're 12 and possess a cigarette, the fine is $50 in D.C.," Harris said. "That's just plain bad policy. This is the opportunity to stop that bad policy from going forward."
The amendment would not take the law off the books, but would block it from taking effect by barring the district from spending local tax dollars to relax penalties for recreational marijuana. Congress used a similar amendment to block the District from implementing its medical marijuana program for 10 years.
The House Appropriations Committee approved the amendment on a mostly party-line vote, with one Democrat, Rep. Henry Cuellar of Texas, joining 27 Republicans in voting for it.
The ultimate fate of the amendment will likely depend on negotiations between the House and the Democratic-controlled Senate and White House over the spending bill. Similar negotiations in 2011 led to the reintroduction of a ban on the District spending local tax dollars on abortions for poor women, which remains in place. Gray and other District leaders were arrested in a protest outside the Capitol after the White House and the Senate agreed not to remove the abortion ban.
Opponents of the amendment said Harris was inappropriately meddling in local affairs, noting that Maryland is among the 17 states that have decriminalized pot. Lawmakers in the heavily Democratic district pushed decriminalization as a way to end what studies have shown are huge racial disparities in the way pot laws are enforced in the city.
"It just doesn't seem right that the Eastern Shore of Maryland should be able to reach over into D.C. and make laws for D.C.," said Rep. Jim Moran, D-Va. "It's not the way this country is supposed to function."
The Drug Policy Alliance argued that the move could backfire and lead to de facto legalization. Because the spending bill won't be approved until after the District law takes effect, it would only block police from issuing the $25 tickets, the group said.
Pedro Ribeiro, a spokesman for Gray, said officials were reviewing the impact the amendment would have if enacted.