The Second Amendment has never been the U.S. Supreme Court’s favorite constitutional provision.

A curious case last week was a reminder of how gun-shy the court remains. But it also showed how politically explosive the high court’s powers remain, even when it decides not to decide something.

On April 27, the court dismissed as “moot” a case challenging a New York City ban on gun owners transporting weapons outside the city. A lower court had upheld the law, rejecting New York gun owners’ claims that it violated their rights.

But in January 2019, soon after the Supreme Court had agreed to review the matter, the city had abruptly repealed the transport ban. It began arguing that no actual dispute remained to be resolved — hence there was no need for the court to decide whether the former restrictions had violated the Second Amendment.

On a 6-3 vote, in an unsigned, two-page opinion, the court agreed last week and dismissed the case.

Sounds unexciting. But this nondecision over a settled dispute triggered quite a crossfire. Gun-rights advocates are unhappy that the court found their victory sufficient. So is Supreme Court Justice Samuel Alito, who wrote a spirited, 31-page dissent to the two-page majority ruling. He was joined by conservative Justices Clarence Thomas and Neil Gorsuch (an appointee of President Donald Trump). Trump’s other nominee to the court, Brett Kavanaugh, wrote an unusual separate opinion agreeing with the majority that this particular case is moot, but noting that he shares most of Alito’s views on the underlying gun-rights issues.

Fiery debate over whether the court should address those underlying issues had preceded the ruling for a year, in dozens of friend-of-the-court briefs. In one, five fiercely liberal U.S. senators had accused conservative justices of pursuing “a political project,” and warned that the court would soon be “restructured” if it did not “heal itself.”

The reason for all the high drama is this: The New York case was the first time in a decade that the Supreme Court had agreed to consider a dispute about what the Second Amendment means.

Back in 2008, in its landmark District of Columbia v. Heller decision, the court had held for the very first time that the U.S. Constitution guarantees Americans an individual right to own a gun. (Before that ruling, the court hadn’t accepted a case requiring it to interpret the Second Amendment in almost 70 years.)

The Heller ruling is to progressive gun control advocates what Roe v. Wade is to the anti-abortion movement — a judicial atrocity that invented a “right” that unjustly blocks communities from making laws they think proper through elected institutions. In this case those would be gun-control measures aimed at combating America’s tragic epidemic of gun violence.

Over the past decade, as Alito’s dissent complained, the Supreme Court has declined a number of opportunities to review lower-court rulings interpreting the right established in Heller. Often (too often for gun-rights advocates) appeals courts have ruled that the Heller precedent still permits various kinds of state and local gun regulations.

So when the court agreed to review the New York case, gun-rights advocates hoped — and gun-control proponents feared — that a Trump-reinforced majority of conservative justices was at last ready to make clear that the Second Amendment right “to keep and bear arms” was more absolute than some lower courts have been imagining.

Rather than defend its law and risk such a clarifying ruling, New York politicians apparently chose to beat a hasty retreat, repealing their transport ban and arguing, with a chorus of gun-control advocates by their side, that the court should in effect declare victory for the Second Amendment and move on.

This tangled tale shows how America’s extremist factions have tied the nation into knots on guns — as on so many issues today. No doubt there exists a moderate majority on gun policy that favors many proverbial “common-sense” gun laws — background checks, limits on certain kinds of weapons and ammunition, and so forth — but genuinely respects the basic right for the law-abiding to own guns.

Yet all the firepower is generated by two uncompromising groups — Second Amendment purists who claim a constitutional right to carry almost any type of weapon anywhere they please, and gun-control purists who would disarm America if they could.

What’s curious is that the Heller ruling in fact is not the unqualified endorsement of unlimited gun rights both of these groups often seem to think it is. It is closer to the common-sense middle ground that extremists of both kinds reject.

Consider the details: Dick Heller was a special police officer in Washington, D.C. In his day job he worked as an armed guard at the Federal Judicial Center. He wanted to keep a handgun at home for self-defense. But a far-reaching (overreaching?) D.C. gun ordinance made that illegal.

The court heatedly debated the ambiguities of the Second Amendment — which declares the necessity of a “well-regulated militia” before guaranteeing “the right of the people to keep and bear arms.” It ruled 5-4 that whatever the exact boundaries of the right protected, it surely permits an impeccably law-abiding American like Heller to keep a commonplace type of weapon in his own home.

But Justice Antonin Scalia made it clear that “the Second Amendment right is not unlimited. It is not a right to keep and carry any weapon whatsoever in any manner whatsoever … . The Court’s opinion should not be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons and the mentally ill, or laws forbidding … firearms in sensitive places such as schools and government buildings, or laws imposing conditions … on the commercial sale of arms … .”

No wonder appeals courts are coming to different conclusions about how far gun regulations can go. Some clarification from the Supreme Court might be helpful.

But it seems the only way we can get that, given the mutual suspicions of gun-rights and gun-control factions — and the Supreme Court’s own persistent discomfort with Second Amendment mysteries — is something like the weird process on display last week.

Apparently, whenever the Supreme Court deigns to consider a Second Amendment appeal of a new gun-control law — that’s a signal that the law in question should be repealed, rendering the case moot before it forces the court to be any clearer about the extent of gun rights.

This is no way to run a constitutional republic — but for now it may be the best America can do.

D.J. Tice is at Doug.Tice@startribune.com.