In 1934, Congress responded to a wave of Prohibition-era gun violence by passing the National Firearms Act, a statute that banned “machineguns” and devices “designed and intended…for use in converting a weapon into a machinegun.” Bump stocks are one such device: specialized stocks that make it easier to fire a lot of rounds in a short period of time. A rifle with a bump stock can fire between 400 and 800 rounds per minute; for comparison’s sake, a fully automatic machine gun can fire between 700 and 950 rounds per minute. In 2017, a gunman killed 60 people at a music festival in Las Vegas thanks to bump stocks, which enabled him to fire into the crowd at a rate of about 540 rounds per minute.

On Friday, the Supreme Court’s conservatives ruled that none of that matters. In a 6-3 opinion written by Justice Clarence Thomas, the Supreme Court ruled in Garland v. Cargill that the federal Bureau of Alcohol, Firearms, Tobacco and Explosives exceeded its authority by issuing a rule after the Las Vegas shooting that classified guns equipped with bump stocks as machine guns. To justify its decision, the Court trotted out the most authoritative source of law in the American canon: Clarence Thomas’s personal understanding of how firearms work, supplemented with diagrams of a gun’s internal mechanisms, helpfully supplied to Thomas by the Firearms Policy Coalition Action Foundation.

“A semiautomatic rifle equipped with a bump stock is not a machinegun because it cannot fire more than one shot by a single function of the trigger,” Thomas wrote. “All that a bump stock does is accelerate the rate of fire by causing these distinct functions of the trigger to occur in rapid succession.” Both a machine gun and a gun equipped with a bump stock let a shooter pull a trigger once and spray a hose of bullets. But Thomas invented a legal difference because, technically, what is happening inside the gun hasn’t changed.

The opinion in Cargill combines the worst aspects of the conservative supermajority’s pedantic obsession with rigid textualism and its push for expanded gun rights. Thomas focuses on meaningless minutiae at the expense of the people who are going to die in mass shootings and the policymakers who passed a law clearly designed to prevent exactly that.

Federal law defines a “machinegun” as “any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger.” The definition also includes “any part designed and intended . . . for use in converting a weapon into a machinegun.” After the tragedy in Las Vegas made abundantly clear that bump stocks function as machine guns, President Donald Trump instructed the ATF, which has rulemaking authority under the National Firearms Act, to act. ATF did so in 2018, clarifying that the ban covers devices that allow “the firing of multiple rounds through a single function of the trigger”—that is, bump stocks. The rule required owners of bump stocks to destroy them or return them to the ATF.

There is no dispute that a shooter only needs to pull the trigger once to fire a bump stock-equipped gun continuously. But, Thomas says, the statute “does not define a machinegun based on what type of human input engages the trigger.” Instead, he takes readers on a journey through the inside of a gun, complete with (seriously) a GIF, including a link to the Supreme Court’s website that any confused readers can refer to.

Thomas explains that the phrase “single function of the trigger” refers not to the human act of squeezing it with one’s finger, but to how many shots are discharged each time the trigger’s internal components are engaged—which is, in Thomas’s telling, one. So, doing one thing that keeps the trigger continuously engaged firing multiple shots is beyond the reach of the law. “A bump stock does not convert a semiautomatic rifle into a machine gun any more than a shooter with a lightning-fast trigger finger does,” Thomas writes. Apparently, there’s no legal problem with bump stocks because The Flash could do what they do, too. As Sotomayor writes in dissent, this warping of the statutory language is “inconsistent with the ordinary meaning of the statutory text and unsupported by context or purpose.”

In a solo concurrence, Justice Samuel Alito writes that there is “little doubt” that the Congress that enacted the National Firearms Act “would not have seen any material difference between a machinegun and a semiautomatic rifle equipped with a bump stock.” But, he says, “there is simply no other way to read the statutory language” other than, as the Court does, as narrowly as possible. He calls on Congress to step in, but this is window dressing: Alito knows perfectly well that his fellow Republicans will never do anything about guns that might jeopardize their precious gun lobby campaign donations, so the gesture is basically meaningless.

Garland v. Cargill should be a no-brainer. (Sotomayor thinks so, too: “This is not a hard case,” she writes at one point.) The law bans weapons and devices that a shooter could use to fire multiple shots without reloading, and with one function of the trigger. Bump stocks automate the firing process so a shooter only needs to pull the trigger once, without reloading, in order to fire multiple shots. The Court’s willingness to twist itself into rhetorical knots to obscure reality, Sotomayor writes, “enables gun users and manufacturers to circumvent federal law,” and will have “deadly consequences.” The only question is when.

The Court’s ruling is an affront to the English language, human lives, and the theoretically co-equal branches of government trying to protect those lives. In dissent, Sotomayor writes, “When I see a bird that walks like a duck, swims like a duck, and quacks like a duck, I call that bird a duck.” Bump stocks fire like machine guns, and were banned like machine guns. Because of the Supreme Court, they’ll continue to kill like machine guns, too.