The Supreme Court declined Monday to take up a legal battle over the Trump administration's ban on bump stocks, leaving the prohibition on the devices in place.
Brought by a group of bump-stock owners and gun rights groups, the dispute not only took aim at the ban put in place by the Bureau of Alcohol, Tobacco, Firearms and Explosives in the wake of a, but also raised the question of whether the Supreme Court should overrule a decades-old legal doctrine that is a target of conservatives.
Known as the Chevron deference, named for the 1984 case Chevron v. Natural Resources Defense Council, the doctrine requires federal courts to defer to an agency's reasonable interpretation of an ambiguous statute passed by Congress.
Conservatives believe the doctrine gives too much power to agency bureaucrats, and members of the high court's conservative wing, including Chief Justice John Roberts and Justices Clarence Thomas, Samuel Alito and Neil Gorsuch, are skeptical of Chevron.
Because the Supreme Court now has a 5-4 conservative majority, some fear the high court is eager to chip away at Chevron or overturn it completely and warn that could lead to a weakening of environmental, workplace and immigration regulations.
President Trumpthen-Attorney General Jeff Sessions to craft a rule banning bump stocks in February 2018 after a gunman opened fire on concert-goers in Las Vegas, killing 58 and wounding 500. Law enforcement discovered the shooter outfitted several firearms with the devices, which allow semi-automatic rifles to fire more rapidly.
The Bureau of Alcohol, Tobacco, Firearms and Explosivesit would be expanding the definition of "machine gun" under the National Firearms Act to include bump stocks. The ban officially took effect in March, leaving any person with the device subject to a felony.
Bump stock owners and gun rights groups challenged the ban in federal court, but have suffered a string of losses. Lower courts declined the block the Trump administration's ban from taking effect, and in March, the Supreme Courtto halt its enforcement.
In a statement accompanying the Supreme Court's decision not to hear a challenge to the bump stock ban, Gorsuch said he agreed the case does not merit review, but criticized the lower court for applying Chevron when it upheld the ban.
"The agency used to tell everyone that bump stocks don't qualify as 'machine guns,'" he wrote. "Now it says the opposite. The law hasn't changed, only an agency's interpretation of it. And these days it sometimes seems agencies change their statutory interpretations almost as often as elections change administrations." He wondered why the courts should defer "to such bureaucratic pirouetting."
Chevron, he added, "has no role to play when liberty is at stake," citing the criminal penalty associated with owning a bump stock.
In their filing with the Supreme Court, lawyers for the bump-stock owners and gun groups argued that the U.S. Court of Appeals for the D.C. Circuit "applied Chevron deference in a manner that stretches that doctrine beyond its breaking point."
But the Justice Department defended its process for expanding the definition of "machine gun" and argued the case is a "particularly unsuitable vehicle" for addressing questions of agency deference.
"The government has urged throughout this litigation that the agency's application of the statutory definition of machine gun to the bump stocks at issue is the best interpretation of the statute — wholly apart from any question of deference," Solicitor General Noel Francisco wrote in a filing with the Supreme Court urging the justices not to hear the dispute.
Correction: This story has been updated to reflect that the Las Vegas shooting happened in 2017, not 2018.