The Supreme Court heard the most important gun-rights case in 10 years today—one with the potential to be doomsday for gun-control supporters, and a huge win for the National Rifle Association—but may not decide it.

That’s because the case, New York State Rifle & Pistol Association v. City of New York, is probably moot, since New York City (and state) withdrew the challenged regulation after the Supreme Court took the case.

The reason was obvious: With Justice Brett Kavanaugh having replaced Justice Anthony Kennedy on the court, there are probably five votes for overturning the law and, more importantly, expanding the court’s jurisprudence on what the Second Amendment does and does not cover.

New York has three types of firearms licenses, in order of strictness: concealed carry, a “premises license,” and a license to carry during employment. The middle form of license is the subject of today’s case.

The now-repealed version of New York City’s premises license only allowed the licensee to possess the firearm at home and at one of seven shooting ranges in the city—not to carry the gun around, or transport it out of the city for any reason.

Several gun owners sued. One complained he couldn’t take it to his country house upstate. Another wanted to shoot at target ranges outside the city. And so on.

After the Supreme Court took the case, those restrictions were loosened. Under the current law, premises licensees can take their guns to second homes, to places of business, and to shooting ranges outside of the city.

Case closed?

Not when it’s this important an issue. The court has only ruled twice in the last century on how the Second Amendment affects individual gun owners, and since its landmark decision in 2008’s District of Columbia v. Heller, it has repeatedly declined to take gun cases in recent years.

As a result, neither gun-rights activists nor gun-control activists really know what the U.S. Constitution allows as far as gun regulations, and lower courts have begun to diverge from one another. The stakes are high, especially since a decision would probably be rendered just in time for the 2020 election.

So, the challengers maintained, there are still live issues here. What if a gun owner wants to stop for coffee on the way to their country house? (Yes, this was an actual question raised in challengers’ briefs.) And what about the period during which the broader regulations were in place? Couldn’t New York City penalize someone now for breaking the rules then?

But these are thin reeds on which to hang a major constitutional ruling, and in fact, most of the oral argument on Monday was devoted not to the merits of the law, but to the questions of whether there’s even a live case here.

That’s a bad sign for the NRA. While the justices did spend some time talking about the Second Amendment, they spent much more time talking about when cases become moot.

Most importantly, Chief Justice John Roberts seemed inclined toward New York City’s position that the case should be dismissed. He seemed most concerned about the claim that someone who violated the old law could still be prosecuted, but Richard Dearing, the lawyer for New York, said that they could not be and that the state and city had stipulated that they could not be.

As for the other justices, Justices Samuel Alito and Neil Gorsuch seemed convinced that the case was live—and, not coincidentally, that the regulations raised serious Second Amendment issues. Justice Clarence Thomas was silent, as usual, but has recently issued opinions complaining that the Second Amendment has become a “disfavored right” and a “constitutional orphan,” which strongly suggests he would take this case.

Uncharacteristically, Justice Kavanaugh was also silent. He has made many statements supporting an expansive view of the Second Amendment in the past, and court-watchers have generally counted him in the pro-gun camp, but he asked no questions today.

All of the court’s more liberal members seemed convinced that the case was moot, with Justice Ruth Bader Ginsburg parsing the rules of procedure like an expert law professor.

As in many other cases, then, it appears that Roberts will be the swing vote in this one. And if his concern is that gun owners could still be prosecuted for violations under the old law, it appears that concern has been answered.

If the court does come down that way, though, it would be foolish for gun-control activists to declare victory.

First, as we’ve seen in other high-profile cases, Roberts is difficult to predict. He’s a judicial conservative, an institutionalist, a pragmatist, and someone focused on restoring the legitimacy of the Supreme Court.

In this case, both conservative and liberal senators filed amicus briefs urging the court not to let politics dictate their decision—meaning, of course, that whichever way the court rules, the other side will say it is playing politics. For an institutionalist like Roberts, the case is a minefield.

Second, even if New York wins this case, there will be another one soon. At most, a dismissal on mootness grounds is a reprieve for gun-control supporters—not a victory.

Eventually, the court will take a Second Amendment case—possibly one with a more important set of regulations than these somewhat quixotic ones, and with more opportunity to expand the meaning of the Second Amendment. And when that happens, it’s quite likely that Americans’ gun rights will grow, just like the number of mass shootings at concerts, malls, and schools.