"What the states do would not matter if there were serious interest in the subject" on Capitol Hill, said Delaware. Eleanor Holmes Norton, a Democrat who represents the district in Congress. "I don't think there's a serious interest in the subject."
The new sense of urgency has been fueled in part by two studies released this year that found large racial disparities in marijuana arrests in the city. Blacks were eight times more likely to be arrested than whites in DC in 2010, the American Civil Liberties Union found, and 91 percent of those arrested that year were black. About half of the city's 632,000 residents are African-American.
"We have hundreds of young black men, black boys, being locked up, for simple possession of a couple bags of marijuana," said Democratic Councilmember Marion Barry, one of the bill's sponsors. "We don't want to be proud of the wrong kind of thing here. We need to stop that kind of injustice from happening."
Democrat Paul Zukerberg, a defense attorney who represents people charged with marijuana offenses and who campaigned for the council this spring on liberalization of marijuana laws, said he's pleased members have embraced the issue.
"A lot of things came together," Zukerberg said. "This is a movement that's national in fact, it's an international movement. We're part of a larger shift in people's attitudes toward marijuana."
Congress has disapproved of only three pieces of legislation passed by the D.C. Council, the last in 1991. A more frequent tactic for members who disapprove of policies in the heavily Democratic district is to insert language in the city's appropriations bill. That's what then-Rep. Bob Barr, a Georgia Republican, did in 1999 to block the city from spending money on its medical marijuana program, which district voters had approved the previous year.
The so-called rider remained on the city's budget until 2009. After a lengthy regulatory process, medical marijuana became available this year. It's allowed only for patients with HIV or AIDS, cancer, glaucoma, and conditions such as multiple sclerosis that cause severe muscle spasms. City health officials said last month that only 59 patients had registered to buy medical marijuana.
Even with decriminalization, the district is not about to become a pot haven. Possession would still be barred on federal land, which encompasses more than 20 percent of the city. And federal law enforcement officers such as the U.S. Park Police or Capitol Police can make arrests for violations of federal law on local property.
"Decriminalization is a local law," said Janene Jackson, director of the mayor's Office on Policy and Legislative Affairs. "We don't want people thinking you're free to puff up on federal property. You're not, and you will be arrested."
The bill would decriminalize possession of less than 1 ounce (28 grams) of pot. While potential fines haven't been finalized, Democratic Councilmember Tommy Wells, the bill's lead sponsor, is considering $25. That would be lower than the civil fines in any state except Alaska, which has none.
While such laws are widespread on the West Coast and in the northeastern New England states, no state in the mid-Atlantic region has decriminalized pot. In the district, 10 of the 13 councilmembers have signaled their support for the decriminalization bill.
Still, opponents remain. Bernard Howard, pastor of a church in Southeast Washington, said criminal penalties deter some people from smoking marijuana.
"The message is going to be sent that it's really not that bad of a choice of drug," Howard said. He said he smoked pot as a teenager and then moved onto other drugs, but has been drug-free for 20 years.
"I think it's very detrimental to the psychological development and social development of young people that are using marijuana, and especially our young black men," he said.
Others believe the district is being too cautious. Independent Councilmember David Grosso has introduced a legalization bill, although it doesn't have co-sponsors.
Adam Eidinger, a legalization advocate who heads a group called D.C. Marijuana Justice, said decriminalization is a compromise between those who want to keep the laws the same and those who want to legalize pot. Eidinger is weighing a ballot initiative on legalization next year.
"By playing the legalization card, it's getting us decriminalization. I'm sure of that," Eidinger said. "And hey, you know what, if that's what we get out of this, compared to a year ago it will seem like a huge improvement."