A machine gun is a weapon that can continuously fire bullets with one trigger pull. In 2017, a mass murderer killed 60 people in Las Vegas using semiautomatic rifles equipped with bump stocks, which lets a gun fire continuously. It was the deadliest mass shooting in the country's history. This slaughter prompted the Trump administration to ban bump stocks.
On Friday, the Supreme Court ruled that the ban was unconstitutional because the folks who wrote the Constitution, who did their work at a time when smooth-bore, muzzle-loading muskets were the go-to weapon for armies, clearly understood the difference between a machine gun (which is banned) and an accessory (which turns a semiautomatic rifle into the functional equivalent of a machine gun). Or something. In other words, a weapon that is designed for rapid fire is banned, but an attachment that turns a semiautomatic into the functional equivalent of a machine gun is fine. The decision hung on the exact definition of "machine gun," which Congress has banned for civilians.
The decision was 6-3, along party lines (20 years ago, we wouldn't have talked about the Supreme Court voting along party lines, but now, well, that's the way it often is). Maybe there was a split decision because when they were in law school, the two groups had different professors for Gunnery 101, where the students learn about the different kinds of guns so they can better understand the Second Amendment.
In the dissent, Justice Sonia Sotomayor wrote: "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. A bump-stock-equipped semiautomatic rifle fires automatically more than one shot, without manual reloading, by a single function of the trigger. Because, like Congress, I call that a machine gun." Sotomayor read her dissent from the bench, which is very unusual and only done when a justice feels very strongly about a dissent.
The majority generously noted that if Congress wants to change the definition of machine gun to include semiautomatics with bump stocks, it is free to do so. The decision was written by Justice Clarence Thomas, who—surprisingly—wasn't on vacation with Harlan Crow last week. Thomas' opinion was an exercise in sophistry, as he used lots of diagrams and words to argue that guns with bump stocks aren't machine guns because you have to pull the trigger more often on the former than the latter. This raises a pretty basic question: If the bump stocks don't meaningfully increase the rate of fire, then why do people buy them? (V)