Dear John,

As you may have heard, this morning the Supreme Court struck down a federal rule banning bump stocks in Garland v. Cargill.

Bump stocks are dangerous accessories that convert semiautomatic weapons into fully automatic guns that can fire hundreds of rounds per minute. After bump stocks were used to murder 60 people and injure many more at the Route 91 Harvest Music Festival in Las Vegas in 2017—the deadliest mass shooting in American history—the ATF issued a rule categorizing bump stocks as machine guns and therefore banning their ownership.

Now, the Supreme Court has recklessly undone this lifesaving ban and allowed automatic weapons back into civilian life. In his decision, Justice Thomas uses a narrow, technical reading to reach his conclusion that bump stocks don’t cause the type of rapid fire that federal law defines as a machine gun. To no one’s surprise, his reasoning is strained and opaque, and ignores the grave threat these weapons pose to the public.

Our executive director Emma Brown went on MSNBC immediately after the decision to explain just how dangerous this ruling is. Watch below: