Although AR-15 rifles fall under the Second Amendment, the county maintains in its brief that this coverage does not grant Americans an unconditional right to possess the weapons.
On December 2, the Supreme Court will review constitutional challenges to bans on “assault weapons” in Connecticut and Cook County, Illinois, which sweep up rifles broadly owned by the public, including the AR-15. The plaintiffs in those consolidated cases argue that such laws plainly infringe the Second Amendment by prohibiting arms that are in common use for lawful purposes. In briefs filed on Wednesday, Connecticut and Cook County urge the justices to discard that standard, contending that a weapon’s popularity is not determinative. The central question, they say, is whether their restrictions on rifles align with a historical tradition of prohibiting “unusually dangerous weapons.”
Cook County and Connecticut bear the burden of demonstrating that their laws are “consistent with this Nation’s historical tradition of firearm regulation,” the criterion set by the Supreme Court’s 2022 Bruen decision in New York State Rifle & Pistol Association v. Bruen. On the face of it, that is a formidable task.
In the 2008 decision District of Columbia v. Heller, the Supreme Court held that the Second Amendment protects the right to own “bearable arms” that are “in common use” for “lawful purposes like self-defense.” That description clearly includes “AR-15 platform and similar semiautomatic rifles,” the firearms at issue in these cases. Yet Heller also acknowledged “the historical tradition of prohibiting the carrying of ‘dangerous and unusual weapons.'” Cook County and Connecticut contend that the rifles they have deemed intolerable fall into that category.
“There is a robust historical tradition of regulating unusually dangerous weapons that
compromise public safety,” Cook County states. “Such regulations, which long
predate the founding, have included outright bans and other restrictions on exceptionally dangerous weapons like launcegays, trap guns, Bowie knives, and slung shots.”
Cook County argues that its ordinance is “relevantly similar” to those historical restrictions because it targets “exceptionally lethal weapons that are disproportionate to the end of self-defense.” AR-15s are “offensive weapons of war designed for maximum lethality and are not customarily used for self-defense,” the brief asserts. “The purpose and operation of the ban is consistent with our Nation’s historical tradition and accounts for the exceptional dangerousness of these technologically advanced weapons.”
The ban is “an appropriate contemporary restriction implemented by the legislature in response to dramatic technological change and unprecedented societal concern,” the brief says. “It is tailored to respond to the particular dangers presented in areas with mass casualty exposure and acute public safety risk.”
Connecticut offers a similar argument. One problem with this defense is the premise that “assault weapon” bans focus on “exceptionally lethal weapons.” As critics of such laws have pointed out for decades, the features they target, such as folding stocks, pistol grips, and barrel shrouds, do not affect a rifle’s basic operation. With or without them, a rifle fires the same ammunition at the same rate with the same muzzle velocity. And because AR-15s use intermediate-caliber ammunition, they are arguably less lethal than shotguns and many hunting rifles that are not classified as “assault weapons.”
Cook County’s emphasis on technological developments is also questionable. Constitutional guarantees establish principles that courts routinely apply to technologies that did not exist at the founding. Although the Framers did not have radio, television, or the internet, for example, the First Amendment nevertheless constrains government regulation of those media.
More specifically, Heller rejected the idea that modern weapons are not covered by the Second Amendment by recognizing a constitutional right to own semiautomatic pistols. The Supreme Court said “the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding.” The Court confirmed that point in the 2016 case Caetano v. Massachusetts, which involved a state ban on stun guns.
Cook County also asserts that AR-15s are not suitable for self-defense, a claim that would be hotly contested by many owners of such rifles, who commonly report using them for that purpose. “Plaintiffs have shown that AR-15s are well-adapted for self-defense,” U.S. District Judge Peter Sheridan wrote in 2024, when he reluctantly concluded that New Jersey’s AR-15 ban was inconsistent with Heller while expressing his dismay at that result. “Evidence has been presented to the Court that the build of the AR-15 makes it well-suited to self-defense because it is ‘light weight, [has] very mild recoil, and [has] good ergonomics’; it is a weapon which is ‘well suited to younger shooters, female shooters, and other shooters of smaller stature.'”
Sheridan added that “the AR-15’s design features—including the effectiveness of its cartridge for self-defense use and its better continuity of fire when used with available magazines—make the AR-15 a good choice for self-defense.” And he noted that “the AR-15 has been used recently in several, relatively high-profile self-defense events in Florida, Illinois, Texas, Pennsylvania, and Oklahoma.”
Cook County and Connecticut are also mistaken in suggesting that self-defense is the sole “lawful purpose” that matters. While Heller highlighted the use of handguns “in defense of hearth and home,” it did not declare that to be the entire scope of the Second Amendment. On the contrary, the phrase “lawful purposes like self-defense” implies other uses, such as hunting, pest control, and target shooting. The decision explicitly mentioned hunting as a “reason Americans valued the ancient right.”
The briefs are misleading in another way that could prove decisive. They conflate “dangerous and unusual” with “unusually dangerous,” which are not the same thing.
In the 19th century, state legislators restricted (and sometimes banned) weapons such as Bowie knives, spears, sword canes, slungshots, and brass knuckles. But historical evidence indicates those weapons were not targeted simply because they were “unusually dangerous.” Legislators were also concerned about how the weapons were typically used.
Solicitor General D. John Sauer, who filed a brief supporting the challenges to the AR-15 bans, notes that 19th-century laws targeted weapons associated with “duels, brawls, and other criminal activities.” And in reviewing those laws, state courts distinguished between arms favored by criminals and arms commonly used for lawful purposes.
In 1871, the Tennessee Supreme Court held that legislators could ban weapons that were “not usual” but could not ban “the usual arms of the citizen.” The highest courts of Texas, Arkansas, West Virginia, North Carolina, and Michigan agreed that the right to arms encompassed weapons commonly owned by law-abiding people, including rifles.
AR-15s and similar rifles readily pass that common-use test. In January, the National Shooting Sports Foundation, the gun industry’s trade association, reported that Americans own more than 32 million “modern sporting rifles,” its preferred term for the models targeted by “assault weapon” bans. Survey data suggest that somewhere between 16 million and 25 million Americans have owned AR-15‑style rifles. Last year, a unanimous Supreme Court described the AR-15 as “the most popular rifle in the country.”
According to Cook County and Connecticut, however, none of that matters. “Once it is established that a regulation pursues a legitimate public safety objective in a permissible manner, raw ownership numbers cannot immunize a firearm from regulation,” Cook County states. It argues that opponents of its ordinance have misconstrued the significance of the common-use test and misunderstood how it interacts with Bruen.
“When the Second Amendment’s plain text covers an individual’s conduct, the Constitution presumptively protects that conduct,” the Supreme Court said in Bruen. “To justify its regulation, the government may not simply posit that the regulation promotes an important interest. Rather, the government must demonstrate that the regulation is consistent with this Nation’s historical tradition of firearm regulation. Only if a firearm regulation is consistent with this Nation’s historical tradition may a court conclude that the individual’s conduct falls outside the Second Amendment’s ‘unqualified command.'”
The common-use question, Cook County contends, features only in the first Bruen step: “the inquiry whether the weapon at issue is one ‘the Second Amendment protects.'” But even if ownership of AR-15s is covered by “the Second Amendment’s plain text,” it argues, that does not resolve whether they can be banned, which depends on the historical analysis required by the second step of the Bruen test.
“This Court’s decision in Bruen confirms that the Second Amendment’s step-two inquiry does not insulate popularly owned firearms from regulation,” the brief states. In Bruen, it was “undisputed” that “handguns are weapons ‘in common use’ today for self-defense,” including “outside the home.” But “instead of being the end of this Court’s inquiry, that observation was just the beginning.” The decision also included an “extended analysis” of the historical laws that New York cited to justify its “proper cause” requirement for carry permits. “If lawful common use alone were enough to forbid regulation,” Cook County argues, “there would have been no need to engage in that careful and prolonged analysis.”
The question in Bruen was not whether the Second Amendment precludes “regulation.” It was whether New York’s specific approach, which required residents to demonstrate a “special need” before they were allowed to exercise the right to bear arms, was consistent with the historical tradition. That is why the Court considered (and rejected) the purported historical analogs that New York offered.
Cook County conflates requirements for carry permits, the issue in Bruen, with an outright ban on ownership, the policy it is defending. Connecticut likewise blurs the distinction between carry restrictions and complete prohibition.
“The Bowie knife was ‘widely carried by Americans of all stripes,’ including ‘upstanding citizens and villains’ alike,” Connecticut’s brief says. “The widespread use of Bowie knives and other weapons for lawful purposes did not prevent dozens of States from restricting those weapons.” But those laws generally restricted or banned public carry. They rarely made it illegal to acquire or possess a Bowie knife, which is the approach that Connecticut and Cook County have taken with AR-15s.
That policy is hard to reconcile with Heller. I will quote Sheridan again, since his remarks made clear that he would have preferred to uphold New Jersey’s AR-15 ban. Under Heller, he said, “a categorical ban on a class of weapons commonly used for self-defense is unlawful.” Given “the Supreme Court’s clear direction on this point,” he concluded, New Jersey’s law “is unconstitutional” as applied to “the Colt AR-15 for use for self-defense in the home.”
Last July, the U.S. Court of Appeals for the 3rd Circuit agreed and went further, extending that conclusion to “the full class of semi-automatic rifles” banned in New Jersey. “Together, Heller and Bruen teach that bans or broad prohibitions on possessing or carrying of a class of weapons in common use for lawful purposes fail to find support in our Nation’s tradition of firearm regulation,” Judge Arianna Freeman, a Joe Biden appointee, wrote in the majority opinion. “That principle resolves our inquiry here.”
To fend off the challenges to their laws, Connecticut and Cook County will have to persuade the justices that the Third Circuit’s reading of Heller and Bruen is mistaken, meaning they may ban firearms that are commonly used for lawful purposes. That seems like a tall order, and Cook County’s stance is especially perplexing. According to its brief, the mere fact that a weapon is covered by the Second Amendment does not mean Americans possess an unqualified right to own it. The more one considers that claim, the less it adds up.
