Gun bans in Illinois and Naperville should remain in effect while legal challenges work their way through the courts, attorneys for the state and western suburb argue in briefs filed Monday with the U.S. Supreme Court.

The responses were sent to Supreme Court Justice Amy Coney Barrett in her role overseeing the U.S. 7th Circuit Court of Appeals, which last month turned down a request from a Naperville gun shop owner and a gun rights organization to put the bans on hold.

The Naperville City Council approved a local ban on the sale of certain high-powered firearms a month after the deadly mass shooting at last year’s Fourth of July parade in north suburban Highland Park. The state followed suit in January with a law that immediately banned the sale of certain semi-automatic guns as well as high-capacity ammunition magazines statewide.

Robert Bevis, owner of Law Weapons & Supply, and the National Association for Gun Rights challenge both the Naperville ordinance and the state law in their federal lawsuit, arguing the gun bans violate the Second Amendment right to keep and bear arms. The plaintiffs asked the Supreme Court to intervene in late April after both the U.S. District Court and the 7th Circuit declined to issue injunctions while the case is being adjudicated.

In its 44-page filing to the Supreme Court, the state argues that Bevis and the gun group have failed to show that they are likely to succeed in overturning the laws or to prove that it would be appropriate for the high court to step in this early in the proceedings.

“They principally argue that the district court erred in denying a preliminary injunction … but this Court is not a court of error correction,” Democratic Attorney General Kwame Raoul’s office wrote in its response.

Bevis and the gun rights group also failed to show that they would suffer irreparable harm if the law were to remain in place, which might justify an emergency response from the Supreme Court, Raoul’s office argues.

They “have not shown that their inability to purchase or sell a narrow category of firearms — assault weapons and (large-capacity magazines) — will irreparably harm them,” the state says in its response. “By contrast, the Act’s restrictions on assault weapons and (large-capacity magazines) promote a compelling interest in protecting the public and saving lives.”

In a separate 23-page response, lawyers for the city of Naperville argue that just because those challenging the laws “assert that this presents an issue of constitutional import is not a reason for sidestepping the ordinary appellate process.”

If the Supreme Court were to grant the request, “it would suggest that emergency relief is the rule, not the exception,” the Naperville lawyers argue.

In their request for emergency relief, Bevis and the gun rights group argued that there “cannot be the slightest question … that the challenged laws are unconstitutional” because they place restrictions on the sale and possession of weapons that “are possessed by millions of law-abiding citizens for lawful purposes, including self-defense in the home.”

In addition, they said the laws fail to meet the guidelines for permissible restrictions laid out in recent Supreme Court rulings in gun control cases, including a decision last summer in New York State Rifle & Pistol Association v. Bruen, which struck down New York state’s concealed carry law.

How the courts, including the Supreme Court, apply the Bruen decision to bans on high-powered semi-automatic rifles is at the crux of the ongoing legal battles.

Opponents of the state law argue that it is a clear violation of the Second Amendment because it bans weapons that are widely used, while supporters — led by Democratic Gov. J.B. Pritzker, who signed the ban hours after it was passed in January — argue that the laws fall within the historical tradition of regulating and banning “dangerous and unusual” weapons.

It was unclear when the high court would issue a decision on the request for an emergency injunction. Barrett has the option to act alone or refer the matter to the full court.

The state’s gun ban faces several other legal challenges in both federal and state courts.

The 7th Circuit last week placed on hold a ruling from a federal judge in the Southern District of Illinois that had temporarily blocked enforcement of the state ban.

In addition to the Naperville case, the federal court for the Northern District of Illinois also ruled in favor of the state late last month in a case brought by a Chicago emergency room doctor.

Next week, the Illinois Supreme Court is set to hear oral arguments in a legal challenge brought by Republican state Rep. Dan Caulkins of Decatur and others.

dpetrella@chicagotribune.com