In 2025, the Supreme Court Was One Vote Short on an Assault Weapons Case. This Term It's Deciding One.

The Supreme Court's new term opened October 5 with two cases that test how far a state can go without Congress's sign-off. One asks whether Illinois and Connecticut can ban semiautomatic rifles like the AR-15 by name. The other asks whether Arizona can require voters to produce documentary proof of citizenship beyond what the federal registration form demands. Both are set for argument in December, and neither ruling is expected before the term ends next June, well after this cycle's midterms are decided.

What the ordinances actually ban

Cook County's ordinance defines a banned assault weapon as a semiautomatic rifle that can accept a detachable magazine holding more than ten rounds, combined with features such as a pistol grip or a muzzle brake, plus a list of specific enumerated models that includes the AR-15. The Seventh Circuit upheld that definition. A companion case, Grant v. Higgins, challenges a similar Connecticut law that the Second Circuit also upheld. The Supreme Court consolidated the two cases for a single argument on December 2.

An earlier case, Snope v. Brown, challenged Maryland's near-identical ban. The Fourth Circuit upheld it, and in June 2025 the Supreme Court declined to review that ruling, leaving it in place. Justice Clarence Thomas dissented from the denial. Justice Brett Kavanaugh wrote a separate statement respecting the denial, signaling he expected the court to take up the question once more circuit courts had ruled on it, rather than before. Sixteen months later, with the Seventh and Second Circuits both now on record, the court agreed to decide it.

The legal question traces back to the common use test the court set out in its 2008 Heller ruling: a weapon widely owned by law-abiding people for lawful purposes is presumptively protected. Joseph Blocher, a Duke University law professor who studies Second Amendment litigation, said the case forces the court to confront functional distinctions it has avoided until now.

“All these other kinds of either weapons or weapons accessories have big functional differences and potential serious implications for how those guns work for purposes of self-defense or for purposes of mass murder. That's a hard thing for constitutional law to navigate.”

Robert Cottrol, a law professor at George Washington University, raised a different concern: how a ruling for either side would interact with the 1934 National Firearms Act, the decades-old federal law restricting machine guns. If the court rules that functional similarity to protected weapons controls the outcome, he said, the reasoning could reach further than gun control advocates or Second Amendment groups currently expect.

The voting case Arizona's own attorney general is defending

The second case starts with Arizona's 2022 law, House Bill 2492. It bars anyone who registers using the state's own form, without attaching documentary proof of citizenship such as a passport or birth certificate, from voting for president or Congress. The Ninth Circuit held that the National Voter Registration Act, the 1993 law that created the standard federal registration form, bars Arizona from adding that requirement. Arizona Attorney General Kris Mayes is defending the law at the Supreme Court.

“Arizona has clear authority to make sure the people registering to vote here are actually eligible.”

The Republican National Committee, which intervened to defend the law alongside Arizona Republicans, argues the Constitution's Elections Clause gives state legislatures broad authority over how federal elections are run in that state. Civil rights groups led by Mi Familia Vota counter that the clause has never been read that broadly, and that the federal registration act was written specifically to stop states from layering on extra paperwork. William Baude, a University of Chicago law professor, said the justices have little appetite for the timing of this one.

“The ideal time for the Supreme Court to be pulled into an election would be never.”

Neither ruling will change a single ballot cast this November. Oral argument in both cases is set for December, with decisions due before the term ends next June, after the midterms are settled and before the next presidential primary season begins. What they will settle instead is the baseline for the cycle after that: how much room a state has to write its own voter-eligibility rules, and whether a weapon-specific ban can survive the test the court built for itself in Heller. Both questions sat in the lower courts for years. This is the term the justices finally answer them.