On Oct. 1, 2017, a gunman opened fire on the crowds at a music festival in Las Vegas from the 32nd floor of a hotel across the street. It lasted just 10 horrific minutes. Yet in that time, the shooter fired more than 1,000 rounds, killing 60 people and wounding at least 413. He was only able to achieve this carnage by attaching bump stocks to semiautomatic rifles, radically increasing their rate of fire—from 180 rounds a minute to a maximum of 800 rounds a minute. The bump stocks effectively transformed rifles into machine guns. Donald Trump’s administration quickly took action, clarifying that these dangerous devices are illegal under federal law.

On Wednesday, however, the Supreme Court indicated an inclination, if not an outright hunger, to invalidate the ban. The morning’s oral arguments in Garland v. Cargill provided an ominous sign that five justices may make such weapons of mass slaughter legal once again. Should they follow through, civilians will regain access to a device whose sole purpose is to kill hundreds of people in a single minute.

This gruesome prospect is the result of devious and dishonest lawyering on the part of the gun lobby, abetted by judges who pretend not to know better. The bump stock ban is hardly liberal overreach—it was, after all, enacted by Trump’s Department of Justice in conjunction with the Bureau of Alcohol, Tobacco, Firearms, and Explosives. Nor is it a dubious fit under existing federal law, which prohibits any device that enables automatic firing. But this particular ban sits at the intersection of two obsessions on the legal right: demolishing gun safety legislation and dismantling the administrative state. It was inevitable, then, that the far-right 5th U.S. Circuit Court of Appeals would find the ban unlawful. And given the current Supreme Court’s pro-gun extremism, it was always going to be an uphill climb to persuade a majority that the ban should stand.

To make things easier, let’s count votes at the outset: Justices Clarence Thomas and Neil Gorsuch are vehemently against the bump stock prohibition. Justices Samuel Alito and Brett Kavanaugh are pretty obviously against it, too. The three liberal justices think it is surely legal and should remain in place. Chief Justice John Roberts said little, but seemed to lean in that direction too. That means Cargill likely comes down to Justice Amy Coney Barrett, who has served as a swing justice on guns in the past. Barrett admitted that “intuitively,” she was........

© Slate