The United States Court of Appeals for the District of Columbia has declined to review a July panel ruling striking down Washington, D.C.,’s strict rules for concealed-carry permits.

For District leaders, the appellate court’s decision starts the clock ticking on a choice with potentially momentous consequences for both local public safety and concealed-gun restrictions in jurisdictions around the country.

Washington’s system for granting concealed-pistol permits requires applicants to demonstrate a “good reason” for needing to carry a gun for protection. Three other circuit courts have blessed similar permitting laws elsewhere. The D.C. court, breaking the other way, found this summer that Washington’s rules set the bar so high as to be unconstitutional.

The Washington Post notes that the city now has seven days to ask the district court to hit pause on its decision, which prohibits enforcement of the District’s concealed-gun rules, while it wrestles with whether to take the matter to the Supreme Court.

If Washington opts to abide the district court’s decision and rewrite its law, it will abandon a concealed-carry system it has fought hard to preserve, and which research suggests can result in reduced violence.

Earlier this summer, a professor at Stanford University released a study comparing the kind of strict concealed-carry laws in place in D.C. and a handful of other cities and states against the looser rules followed in most of the country, where gun owners can receive a license to carry in public by meeting minimal requirements (a growing number of states don’t require a license at all).

As we reported in June, the Stanford research found that states with more restrictive concealed-carry laws saw greater drops in violent crime over the 37 years it analyzed.

Door number two for D.C. is a Supreme Court petition. Until now, the Justices have declined to weigh in on whether the Second Amendment grants citizens the right to go armed in public, and if so, whether licensing standards like the capital’s violate that freedom.

Legal observers think that, given the opportunity, the Supreme Court will be likely to take up the case.

“The Second Amendment now means one thing in D.C. and another thing in California. That’s exactly the kind of situation that requires the Supreme Court to step in,” said Adam Winkler., a law professor at UCLA. “The courts have made clear what it means to keep arms, but not what it means to bear arms.”

Should the District move forward with an appeal, its lawyers will confront a Supreme Court that includes Justice Neil Gorsuch, whose appointment the National Rifle Association cheered with a $1 million ad campaign, rather than Merrick Garland, the Obama nominee whose selection was blocked by Senate Majority Leader Mitch McConnell, an NRA ally.

The next court reshuffling could further dim the prospects of D.C. ultimately winning the case.  

Rumors swirl that Justice Anthony Kennedy, an often reliable swing vote, could retire as soon as next year. With Republicans in control of the White House and Congress, it’s likely that anyone nominated to succeed him would look unfavorably upon most gun restrictions.

“D.C. is in a difficult situation,” Winkler said. “Maybe it’s better to have it heard before the Supreme Court now, with Kennedy. But the last time the city went to the Supreme Court over guns” — the monumental Heller ruling was the product of D.C.’s decision to appeal a circuit court ruling rather than effective ban on private gun ownership — “it resulted in a nationwide expansion of the Second Amendment.”