The U.S. Supreme Court on Tuesday declined to take up a challenge to a lower court decision denying a temporary injunction against Illinois’ sweeping gun ban, but Justice Clarence Thomas wrote that the high court should accept the full case if it comes back for review and expressed deep reservations about the ban’s constitutionality. “In my view, Illinois’ ban is ‘highly suspect because it broadly prohibits common semiautomatic firearms used for lawful purposes,’” Thomas wrote, citing case law to bolster his position. “It is difficult to see how the Seventh Circuit could have concluded that the most widely owned semiautomatic rifles are not ‘Arms’ protected by the Second Amendment.” Thomas wrote that the Supreme Court must not permit the U.S. 7th Circuit Court of Appeals in Chicago, which denied the injunction, to  “relegate the Second Amendment to a second-class right.” “This Court is rightly wary of taking cases in an interlocutory posture. But, I hope we will consider the important issues presented by these petitions after the cases reach final judgment,” Thomas wrote. Justice Samuel Alito, who like Thomas is a member of the high court’s conservative wing, broke from the majority opinion and said he would have have allowed the court to hear oral arguments on the case even in its preliminary stages. The high court’s decision comes nearly two years after the incident that led to the ban on certain high-powered guns and high-capacity magazines, a mass shooting at a Fourth of July parade in Highland Park that claimed the lives of seven people and left dozens of others injured. The case stems from a consolidation of several lawsuits filed by gun rights proponents including the owner of a Naperville gun shop against Gov. J.B. Pritzker’s administration and Illinois Attorney General Kwame Raoul. One of those cases is set for a trial later this year in a southern Illinois federal court. Gun control advocates praised the high court’s decision to not take up the case, which allows  Illinois’ gun ban to remain intact. “The Supreme Court action means the protection of Illinois citizens from assault weapons and large capacity magazines will remain in effect. That’s good news for all of us,” said John Schmidt, a former U.S. associate attorney general and executive board member of the Gun Violence Prevention Political Action Committee, also known as G-PAC. “The Court’s action today is another positive sign that Second Amendment rights do not conflict with sensible gun laws that protect the public against criminal violence.” The Illinois State Rifle Association, one of the first groups to file lawsuits last year against the firearms ban, said it was “very disappointed” in Tuesday’s ruling but will continue to fight the ban. “Too much is at stake, and the ISRA remains on the front lines and continues to stand up to Gov. Pritzker and anti-gun legislators in Springfield,” ISRA Executive Director Richard Pearson said in a statement. “Our objective from the very beginning of the process that started the moment Gov. Pritzker signed the bill into law was to take our case to the United States Supreme Court. And we followed through on that promise, and despite today’s decision, if given the chance, we’d do it all over again because it is the right thing to do.” Gun rights advocates have filed several lawsuits against Illinois’ gun ban on both the state and federal level. The legal challenges rely heavily on the landmark 2022 case of New York State Rifle & Pistol Association v. Bruen, in which the U.S. Supreme Court established a new constitutional standard holding that gun laws today shall be historically consistent with laws on the books in the 18th century, when the Second Amendment was codified. Most court decisions so far have been in the state’s favor, although last year U.S. District Judge Stephen McGlynn, whose district covers the southern portion of the Illinois, ruled the gun ban was likely unconstitutional in granting a preliminary injunction. His decision was later overturned by a three-judge panel from the U.S. 7th Circuit Court of Appeals. In November, the appeals panel found that “at least since the Founding there has been an unbroken tradition of regulating weapons” to protect public safety and that the state and local laws at issue “stay within those boundaries.” “There is a long tradition, unchanged from the time when the Second Amendment was added to the Constitution, supporting a distinction between weapons and accessories designed for military or law-enforcement use, and weapons designed for personal use,” the appeals panel’s majority wrote, finding that the newly banned weapons fit into the former category. “The legislation now before us respects and relies on that distinction.” In a dissenting opinion, Justice Michael Brennan, an appointee of President Donald Trump, rejected the majority’s “remarkable conclusion” that the banned weapons and attachments do not qualify as “arms” that fall under the rights granted by the Second Amendment, finding that they indeed do “warrant constitutional protection.” The National Shooting Sports Foundation, a plaintiff in one of the Illinois lawsuits, has cited Bruen’s “historical traditional test” to contend the state’s ban on many semi-automatic guns — in which each round requires a trigger pull — is too broad because it prohibits guns that are commonly used by law-abiding citizens. The shooting sports foundation, which is a firearms industry trade group, has noted there have been more than 24 million so-called modern sporting rifles in circulation in the U.S. since the early 1990s, including many AR-15- and AK-47-type guns that are subject to the Illinois ban. In the opinion issued on Tuesday, Thomas noted that the Supreme Court has “never squarely addressed what types of weapons are ‘Arms’ protected by the Second Amendment.” He also wrote that the Seventh Circuit’s decision “illustrates why this Court must provide more guidance on which weapons the Second Amendment covers.” “These petitions arise from a preliminary injunction, and the Seventh Circuit stressed that its merits analysis was merely ‘a preliminary look at the subject,’” Thomas said. “But, if the Seventh Circuit ultimately allows Illinois to ban America’s most common civilian rifle, we can— and should— review that decision once the cases reach a final judgment.” Last month, Thomas was on the losing end of another gun case before the high court where Bruen was a central issue. In that case, United States v. Zackey Rahimi, the high court ruled 8-1 to uphold a three-decade-old gun ban for people accused of domestic violence and subjected to orders of protection. Thomas, the lone dissenter, argued unsuccessfully that the government “failed to produce any evidence” that the law “is consistent with the Nation’s historical tradition of firearm regulation.” McGlynn, appointed to the bench in 2020 by Trump, has set a Sept. 16 trial date over the gun ban’s constitutionality. Illinois’ ban on certain high-powered guns prohibits the delivery, sale, import and purchase of more than 100 so-called assault weapons, in the form of semi-automatic rifles, shotguns and handguns. Also banned are the delivery, sale and purchase of magazines of more than 10 rounds for long guns and 15 rounds for handguns. Illinois’ ban also prohibits “any device or attachment of any kind” that is “designed to shoot, or can be readily restored to shoot, automatically more than one shot without manually reloading by a single function of the trigger.” People who owned guns covered by the ban before Jan. 10, 2023 — the day Pritzker signed the ban into law — but didn’t register them with the Illinois State Police by Jan. 1 of this year, could be charged with a misdemeanor for a first offense and felonies for subsequent violations, according to the gun ban law. Many law enforcement officials have declared, however, that they had no intention of proactively investigating those who violate the law. Over a series of public hearings in recent months, gun rights advocates expressed confusion over the registration process, particularly on what they view as varying definitions of certain firearm accessories that need to be registered. Through Dec. 31, 29,357 people had registered nearly 69,000 prohibited guns and over 42,000 accessories, according to Illinois State Police data. About 2.4 million Illinoisans have firearm owner’s identification cards, meaning only about 1.22% of FOID card holders registered guns or accessories subject to the ban, data show. More gun owners have since registered their firearms and gun accessories, however, the true degree of compliance with the law is not possible to determine since one who has a valid FOID card may not necessarily own guns or accessories that are subject to the ban, or own any firearms at all. Tribune reporter Dan Petrella and The Associated Press contributed.