The Supreme Court is set to hear arguments in December in Viramontes v. Cook County, a case that could reshape the legal landscape for gun control. At issue are state and local bans on AR-15 semiautomatic rifles, which challengers argue are protected by the Second Amendment because they are “in common use” for self-defense. Defenders of the bans counter that these firearms are “weapons of war” with no place in civilian life.
But both sides may be missing the constitutional crux: the Second Amendment’s explicit reference to the “militia.” As Matthew Cavedon, director of the Cato Institute’s Project on Criminal Justice, argues in a friend-of-the-court brief, AR-15s are precisely the type of small arms historically associated with militia service. That history, he contends, places them at the center of the amendment’s protections, not on the periphery.
The amendment’s text is unique in pairing an individual right with a collective purpose: “A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.” Gun-control advocates have long read the prefatory clause as limiting the right to militia service, a view echoed in Justice John Paul Stevens’s dissent in District of Columbia v. Heller. But the Heller majority, led by Justice Antonin Scalia, interpreted the militia broadly, noting that it historically included “all able-bodied men” and that the “free State” referred to a free polity, not state governments.
Scalia’s opinion emphasized that an armed populace serves multiple ends: repelling invasions, suppressing insurrections, and deterring the rise of “large standing armies” that could threaten liberty. Most critically, a “people’s militia” could resist tyranny, a purpose that would be undermined if the government controlled the only armed forces.
The Heller court was careful to exclude “dangerous and unusual weapons” from protection, and it acknowledged that bans on military-style arms like M-16s might be permissible. But the historical record shows that at the founding, citizens were expected to keep small arms suitable for infantry duty—portable, individually operated firearms—not crew-served artillery. The AR-15, a semiautomatic rifle that is lighter and more portable than its fully automatic cousin, the M-16, fits squarely within that tradition.
This case arrives amid broader legal battles over gun policy. The Supreme Court has recently expanded Second Amendment protections, and lower courts are grappling with how to apply those rulings. The outcome in Viramontes could set a precedent for challenges to assault-weapon bans across the country, with potential ripple effects on other firearms restrictions.
As the justices prepare to weigh in, they face a choice: whether to draw an ahistorical line between guns used for self-defense and those deemed “weapons of war.” The Cato Institute’s brief urges the court to reject that dichotomy, arguing that the Second Amendment’s militia purpose actually supports protecting AR-15s. The decision, expected later this term, will likely influence not only the fate of Cook County’s ban but also the broader debate over the scope of the right to keep and bear arms.
