In an unsigned order with no dissents, the justices rejected an emergency appeal that asked them to block a local ordinance and the state ban from taking effect.
While the court’s action is not a ruling on the broader constitutional issue, it is a good sign for California and the eight other states that also ban the sale of assault weapons.
Usually, justices would block a new law from taking effect if they believe it is unconstitutional.
The case was National Assn. for Gun Rights vs. Naperville.
The 7th Circuit Court of Appeals in Chicago said it would hear arguments on the constitutional issue in late June, and the justices may have decided to wait for its ruling.
The high court has not ruled directly on whether an AR 15-style rifle is protected under the 2nd Amendment. In the past, it had turned away 2nd Amendment challenges to similar state and local laws.
But last year, gun-rights advocates were cheered when the more conservative court struck down the laws in New York and elsewhere that restricted many law-abiding gun owners from carrying a concealed weapon in public.
Writing for a 6-3 majority, Justice Clarence Thomas said gun restrictions can be upheld only if they are “consistent with the nation’s historical tradition of firearms regulation.”
Less than two weeks after that decision was announced, a shooter armed with a semiautomatic AR-15 rifle and 30-round magazines opened fire on an Independence Day parade in Highland Park, Ill. The weapon allowed the shooter to fire 83 rounds in less than a minute, killing 7 and wounding 48.
In response, the city of Naperville and the state of Illinois adopted new laws to forbid the sale and possession of assault weapons and high-capacity magazines. Only the sale ban was due to take effect immediately, and a gun store owner and several gun-rights groups sued to block the measures as violations of the 2nd Amendment.
Gun rights advocates argued that millions of AR-15s have been sold in this country and that the 2nd Amendment has been understood to protect firearms that are in “common use.”
But today’s lightweight, semiautomatic weapons are quite unlike the heavy and cumbersome muskets that were in use in 1791. In defense of the ban, state’s lawyers argued these rapid-fire rifles “were developed and marketed as military-style offensive weapons rather than as a means for self-defense.”
A federal judge agreed and allowed the Naperville ban to take effect.
“The history of firearms regulation establishes that governments enjoy the ability to regulate highly dangerous arms,” said U.S. District Judge Virginia M. Kendall, and “assault weapons and large-capacity magazines fall under this category.”
The 7th Circuit Court refused to block both laws from taking effect while it considered an appeal from the gun owners.