In the U.S. Supreme Court (SCOTUS) arguments for New York State Rifle & Pistol Association Inc. v. City of New York almost all time seemed to be devoted to the question of mootness.
This case is a challenge to New York City's previous regulations preventing people with premise-licenses for guns from traveling outside the city with their guns. The primary challenge was centered on the ability of gun owners to take their guns to second homes or shooting ranges outside the city.
In a five-year process, the City of New York continued to defend the law and won at the appellate court level. The plaintiffs appealed to SCOTUS and were granted certiorari. Once SCOTUS granted certiorari, New York City and the State of New York worked together to eliminate the regulations and placed some new regulations at the state level as well as creating state-level preemption of local regulations.
The City of New York argued that with the elimination of the regulations, the case was moot and any challenge of the new regulations was a new conflict that would need to work its way through the courts.
Plaintiffs argue that the case is not moot and SCOTUS should rule on the merits of the case, including declaring the previous regulations unconstitutional. Defendants argue that the case is moot and there is no need to rule on the merits.
My understanding is that if SCOTUS declares the conflict to be moot then it will remand the case to the lower courts to reverse or vacate the judgments.
An argument can be made that the State of New York and New York City would not have changed their regulations had SCOTUS refused to review the case. Following that logic, New York City got an extra five years of a seemingly unconstitutional regulation (in the transcript counsel for NYC agreed that some of the reasons for their regulation were not sound). If SCOTUS grants NYC's requests in their argument then this case goes away and a new case has to be started regarding the new regulations.
Though the precedent of this particular case may go away, the legal standard established by the second circuit seems to be freely available to any new cases. If SCOTUS ruled the regulations unconstitutional then they would also be setting a new legal standard upon which such regulations would be weighed.
What is to prevent municipalities from implementing mootness as a strategy to maintain unconstitutional regulatory structures?
EDIT to address comments and a vote to close
Gun-related cases, whether second amendment or commerce-clause related, have generated significant circuit splits. Significantly, the Supreme Court has not taken cases designed to end the splits.
The second circuit has been seen as friendly to gun-control efforts. That court upheld a ban on large capacity magazines and semiautomatic assasult weapons; a case that SCOTUS declined to review. Additionally, the second circuit also upheld New York's concealed carry law's "proper cause" requirement which SCOTUS declined to review despite a circuit split.
It had been 10 years since SCOTUS had agreed to review a second-amendment related case. Because New York is in the second circuit, and the second circuit has been friendly to gun control efforts in past rulings and SCOTUS has not taken a second amendment related case even when circuits have split, it's not completely unreasonable to assume that New York felt confident in it ability to retain their unique regulation.
Since the Heller ruling, there has been a strategy by governing bodies to avoid SCOTUS review of second-amendment related cases. For this particular law, there's significant mention of New York City's efforts to avoid SCOTUS review in this case:
New York Times: "Fearing Supreme Court Loss, New York Tries to Make Gun Case Vanish"
And, finally, NYC Rules proposal to amend the Premise Handgun License Rules specifically mentions SCOTUS' acceptance of this particular case in their desire to change the rules.
It's not unreasonable to argue that governing bodies located within gun-control-friendly circuits have counted on positive outcomes at the circuit level and lack of review by SCOTUS and governing bodies within circuits that are not gun-control-friendly have withheld appeals to SCOTUS to avoid having laws struck down in a way that would have a nationwide impact.
I did not want this to be about gun control, but, perhaps, this is unique to gun control jurisprudence. I'm truly curious about an overall legal strategy of using the judicial system and mootness to implement regulations in a way so as to avoid SCOTUS review as long as possible by using a strategy as follows:
1) Implement regulation in a circuit friendly to the governing body's position so as to avoid preliminary injunctions
2) Allow the regulation to remain through whatever level of appeal remains friendly
3) Once accepted for review by a potentially unfriendly appeals court, rescind the regulation and look for a declaration of mootness
4) Implement a similar enough regulation to satisfy the governing body but different enough to cause a "new conflict" to exist and start again at step 2
Until the circuit splits are resolved by SCOTUS then it is likely that more cases such as this will arise.
The question remains: Other than SCOTUS settling the issue, what prevents governing bodies from using mootness as a strategy to maintain unconstitutional regulations?