The petitioners’ merits brief filed August 28, 2026, in the consolidated Supreme Court case testing whether AR-15 bans violate the Second Amendment, contains an argument that has drawn far less attention than it deserves. The case is Viramontes v. Cook County, No. 25-238, consolidated with Grant v. Higgins, No. 25-566 — Cutberto Viramontes’s challenge to Cook County, Illinois’s rifle ban, joined with Eddie Grant, Jr.’s challenge to Connecticut’s ban, brought against DESPP Commissioner Ronnell Higgins. The question presented asks whether the plain text and history of the Second Amendment protect the semi-automatic rifles, AR-15s and AK-pattern rifles alike, that Americans have owned in the tens of millions for decades. I expect the answer to be an emphatic yes. But the argument I want to draw out is not about rifles. It is about who decides.
A Test That Empowers, Not Constrains
Some gun owners hear “common use” and worry it hands government a foothold — that a court or a legislature might someday declare an arm uncommon and ban it. The brief’s actual argument runs the opposite direction. It is the American people, through their own purchasing and ownership decisions, who determine which arms are in common use, and therefore protected. Neither a judge nor a legislature performs that calculation. They only observe it.
That is not new doctrine. It is Heller itself. In 2008 the Supreme Court struck down the District of Columbia’s absolute ban on handguns after concluding that the only historical tradition capable of justifying a ban on an entire class of arms is one directed at weapons that are dangerous and unusual. Handguns, already ubiquitous in American homes, could not be both. Bruen then cited Heller favorably some forty times, reaffirming rather than displacing it. Any argument that Bruen somehow erased Heller’s common-use holding is, in my view, simply wrong, and this brief says so directly:
Under Heller, law-abiding citizens have a right to possess AR-15s and similar semi-automatic rifles because AR-15s and similar semi-automatic rifles are covered by the plain text of the Second Amendment… in an arms ban case such as this one, however, Heller has already conducted the historical analysis and decided that the “in common use” test governs.
The Militia’s Assumption: Bring Your Own Arms
The brief roots the common-use test in a second historical thread that reinforces the first: militia service. The Militia Act of 1792 required enrolled militiamen to muster with their own privately owned muskets or rifles, bayonets, ammunition, and equipment. The ordinary citizen supplied the ordinary arm he already kept at home — a rifle, a fowling piece, occasionally a handgun. The government did not select the model. The citizenry did, simply by owning what it already owned.
Heller wove that history directly into the common-use standard, finding it “consonant with the fact that the traditional militia was formed from a pool of men bringing arms in common use at the time for lawful purposes.” The brief carries that principle to its natural conclusion: the arms a free people commonly keep for lawful purposes, including self-defense against every form of violent threat a citizen might face, are the same arms the Constitution protects. That is not a loophole in the text. It is the text’s operating logic.
Justice Thomas States the Principle
The brief is most direct where it draws on Justice Thomas. Dissenting from the denial of certiorari in Snope v. Brown, 145 S. Ct. 1534, 1537–38 (2025), Thomas wrote that the Constitution allows the American people, not judges, to decide which weapons are useful for self-defense, and that courts must look to the standard set by American society itself. That principle recurs across his opinions. In Friedman v. City of Highland Park, 577 U.S. 1039 (2015), dissenting from the denial of certiorari and joined by Justice Scalia, Thomas observed that roughly five million Americans owned AR-style semi-automatic rifles and that the overwhelming majority used them lawfully — under the Court’s own precedent, he concluded, that is all the Second Amendment requires. In Caetano v. Massachusetts, 577 U.S. 411 (2016), Justice Alito, concurring in the judgment, applied the identical logic to stun guns, noting that hundreds of thousands had been sold to private citizens who may lawfully possess them in forty-five states.
Why This Protects Arms Not Yet Invented
The forward-looking implication is the part I find most compelling. Heller recognized that an arm considered dangerous and unusual at the Founding, such as the handgun arguably was under some colonial carry restrictions, can migrate into constitutional protection once it becomes common. The brief quotes Bruen’s explanation directly: those founding-era laws “provide no justification for laws restricting the public carry of weapons that are unquestionably in common use today.” Common use is a contemporary test, not a museum piece.
Run that logic forward. If some weapon not yet invented becomes, through the lawful choices of millions of Americans, part of ordinary civilian life a decade or three decades from now, the Second Amendment’s protection travels with it. Sovereignty over the category belongs to the people who buy, keep, and use these tools for self-defense against every form of tyranny — foreign, domestic, or criminal. It does not belong to the government asked to justify a ban, and it does not belong to the judge asked to referee one. That is the principle I have pressed in my published scholarship for years, and it is the principle I expect a Supreme Court majority to adopt when it rules, not just for the AR-15, but for whatever comes after it.
This article is based on analysis by Professor Mark W. Smith, constitutional attorney and Host of the Four Boxes Diner 2nd Amendment channel. Watch the original video here. This does not constitute legal advice.