A divided US Supreme Court declined to consider a new expansion of constitutional gun rights, turning away challenges to a Maryland ban on so-called assault weapons and a Rhode Island prohibition on high-capacity magazines.

The justices left intact federal appeals court decisions backing the bans against attacks under the Constitution’s Second Amendment.

Conservative Justices Clarence Thomas, Samuel Alito and Neil Gorsuch said they would have heard the appeals. A fourth — Justice Brett Kavanaugh — called the decision upholding the assault weapons ban “questionable” and said the Supreme Court should take up the issue in the next year or two after more lower courts have weighed in.

The dynamic suggests that two other Republican appointees — Chief Justice John Roberts and Justice Amy Coney Barrett — will likely cast the deciding votes. Because four justices are enough to grant review, the three dissents indicate that Roberts and Barrett voted to reject the appeals. Neither gave an explanation.

The cases could have had a broad impact had the court accepted them. Ten states outlaw what critics call assault weapons, a class of semiautomatic rifles that have repeatedly been used in mass killings, and 14 ban high-capacity ammunition-feeding devices, according to Giffords Law Center, an interest group that supports gun restrictions.

The Supreme Court has steered clear of new Second Amendment cases since upholding a federal gun ban for people under domestic violence orders in June. In a non-constitutional case, the justices in March upheld Biden administration rule regulating build-at-home “ghost gun” kits.

Gun-rights advocates were trying to extend the 2022 Supreme Court decision that declared a constitutional right to carry a firearm and established a tough new test for assessing restrictions.

The 4th US Circuit Court of Appeals upheld the Maryland law on a 10-5 vote. Writing for the majority, Judge J. Harvie Wilkinson III said the measure outlawed “military-style weapons designed for sustained combat operations that are ill-suited and disproportionate to the need for self-defense.”

A Maryland resident and three interest groups contended that the law prohibits weapons owned by millions of Americans for legitimate purposes that include self-defense. The 4th Circuit ruling “blesses a ban on the most popular rifles in American,” the challengers argued.

The case is Snope v. Brown, 24-203.

In the Rhode Island case, a unanimous panel of the Boston-based 1st Circuit said the law was probably constitutional. The 2022 law bars the possession of gun magazines capable of holding more than 10 rounds. The measure gave people who already owned high-capacity devices 180 days to alter, surrender or transfer hem.

The laws are supported by Everytown for Gun Safety, an advocacy group founded and backed by Michael Bloomberg, founder and majority owner of Bloomberg News parent company Bloomberg LP.

The case is Ocean State Tactical, v. Rhode Island, 24-131.

Copyright 2025 Bloomberg.