A D.C. resident harvests over a pound of home-grown pot in August. Because of restrictions imposed by Congress, residents can possess and grow but cannot legally buy or sell or smoke the plan outside their homes. (Astrid Riecken/For The Washington Post)

The D.C. Council’s surprise see-saw on loosening marijuana laws Tuesday — and promise to revisit the issue within a month — has set up a vexing period of high-stakes negotiations that could put the council on a collision course with Mayor Muriel E. Bowser and with a Republican-controlled Congress that wishes D.C. voters never legalized weed in the first place.

At stake is a package of regulations that has largely kept pot legalization a low-key affair in the nation’s capital since it was made legal to possess nearly a year ago under a voter-approved ballot initiative. Should D.C. residents be allowed to smoke on the rooftop or sidewalk patios of restaurants? Should they be able to set up discreet pot clubs for smoking in private?

To be sure, the council is split on how far to push the issue. But Tuesday’s debate made clear that the District’s tortured state of partial legalization — in which residents and visitors can possess pot but, thanks to Congress, it remains illegal to buy or sell — is an untenable status quo for a growing number of D.C. lawmakers (especially, it seems, any who are up for reelection).

So what could D.C. do?

An end-run on Congress:

The most aggressive and controversial option available to the mayor and council would use a loophole in federal budget law to let the city fully regulate the sale of marijuana.

But didn’t Congress block D.C. from doing so? Yes. Congress blocked D.C. from appropriating even a cent of its locally generated tax revenue to regulate pot sales in the current U.S. budget. However, under a theory advanced by advocates for D.C. statehood, there is nothing stopping District leaders from declaring an emergency over the condition. That would free them to draw on surplus revenue from past years to pay for drafting new regulations and allotting money for enforcement.

Council member Brianne K. Nadeau (D-Ward 1), who instigated Tuesday’s unexpected drama, said she believes this is the path the District must pursue. “The District can do so. It’s just a question of deciding that we will do it,” she said.

Conservative Republicans in the House are sure to balk, but exactly how far they will push the issue amid a presidential contest in which freedom from federal regulators is a continued party theme is unclear. Congress has taken bipartisan baby steps in the last session toward giving states more rights over marijuana legalization. But D.C. remains a quagmire for Republicans, a jurisdiction where it has long used its broad oversight authority to curtail socially liberal causes advanced by the city’s Democratic majority.

Pot proponents’ more immediate problem, however, is Bowser and Council Chairman Phil Mendelson; neither has been willing to back the plan.

Deregulate . . . and hope for the best:

Another — and highly unlikely — option is to finish what the council started on Tuesday. If a majority of the council declined to extend the ban on smoking in bars and clubs on Feb. 2, the regulations would expire a couple of months afterward and businesses would be free to develop their own rules for marijuana consumption. Unregulated pot clubs could also form, perhaps similar to Spain, where residents pay for membership and access to places to smoke it.

Bowser has said this would lead to an unworkable situation in which the District’s hands would be tied from regulating such establishments under the restrictions put in place by Congress. Bowser also seems to have the votes on the council to keep this from happening. On Tuesday, her close ally in Ward 8, Council member LaRuby May, reversed herself and backed a ban. That decision likely was unpopular with many of May’s constituents in an area of the city where residents still feel that police use marijuana arrests to unfairly target blacks. But Bowser’s financial backing is likely key to May’s re-election.

Compromise:

Perhaps the least controversial plan, if there is to be a loosening of marijuana laws soon, is for the council to take up legislation proposed by Adam Eidinger and other organizers of the initiative that seven in 10 voters backed to legalize pot in the city in 2014.

Eidnger said Tuesday that he is willing to let the city place further restrictions for now on pot distribution, by tightening the definition of “remuneration” under the ballot-measure law. That, he said, would clear up any confusion and expressly prohibit providing monetary donations or services for marijuana.

In exchange, however, Eidinger also wants the city to allow restaurants, clubs, concert halls and other businesses to be rented out for private events that allow marijuana consumption in designated smoking areas.

On select nights, anyone entering those establishments would consent to potentially being around others smoking marijuana. Or maybe all the time, “I think some establishments would go marijuana-only,” he said.