Colorado Gov. Jared Polis (D), signed a bill into law on April 10 requiring people to obtain a permit and undergo safety training before they buy certain guns.

The legislation also bans the purchase and sale of devices that enable guns to be fired rapidly, including bump stocks.

“For folks who haven’t had any gun safety training, it’s very important that they get that, and this bill will make sure that people will get that education on how to operate the weapons safely and—just as important—how to store them safely,” Polis said at a press conference on Thursday.

The Supreme Court’s conservative supermajority carved a huge loophole into the federal prohibition against machine guns on Friday, striking down a bump stock ban first enacted in 2018 by the Trump administration. Its 6–3 decision allows civilians to convert AR-15–style rifles into automatic weapons that can fire at a rate of 400–800 rounds per minute. One might hope a ruling that stands to inflict so much carnage would, at least, be indisputably compelled by law. It is not.

The Supreme Court’s decision invalidating the nationwide bump stock ban ignited a firestorm among Democrats and gun control groups that have long maligned the device used to perpetrate the nation’s deadliest mass shooting. 

The groups expressed worry about not only the impacts of lifting the ban, which could trigger a booming rapid-fire marketplace, but also the other gun cases that remain pending on the justices’ docket. 

The Supreme Court has struck down the reclassification of bump stocks that was promulgated by the Trump administration back in 2018. As I noted earlier this year, this was not a Second Amendment case, but a statutory case, and, as such, the question was not whether bump stocks count as “arms,” but whether the National Firearms Act of 1934 grants the executive branch the power to regulate them in the same manner as it regulates machine guns. As the Court makes clear, the answer to this is unquestionably no. In consequence, the regulation must fall.

In a decision that may mark the low point for blinkered statutory interpretation in the history of the US Supreme Court, the conservative majority has concluded that gun regulators violated the law when they decided that bump stocks turn a semiautomatic rifle into an illegal machine gun.

An Austin gun shop owner succeeded Friday on a years-long quest to overturn a federal ban on bump stocks, winning a 6-3 victory from the U.S. Supreme Court.

Bump stocks are devices that allow semi-automatic rifles to fire hundreds of rounds in a minute. The court ruled the federal Bureau of Alcohol, Tobacco, Firearms and Explosives can not include bump stocks under legislation banning machine guns. The overturned ATF rule required owners of bump stocks to either destroy them or surrender them to the ATF to avoid criminal prosecution.

The U.S. Supreme Court on Thursday ruled that a bump stock does not transform a firearm into an automatic weapon, striking down a federal rule that banned bump stocks. 

In a 6-3 decision, Justice Clarence Thomas wrote, "Congress has long restricted access to "'machinegun[s],'" a category of firearms defined by the ability to "shoot, automatically more than one shot . . . by a single function of the trigger." 

The Supreme Court on Friday overturned a Trump-era ban on bump stocks, ruling that the Bureau of Alcohol, Tobacco, Firearms and Explosives exceeded its authority by determining that the gun attachments turn firearms into machine guns.

The case was decided 6-3, with Justice Clarence Thomas writing the majority opinion and Justice Samuel Alito concurring. Justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson, the courts three liberals, dissented.

What are bump stocks?

If the Supreme Court rules that bump stocks aren’t machine guns later this summer, it could quickly open an unfettered marketplace of newer, more powerful rapid-fire devices.

The Trump administration, in a rare break from gun rights groups, quickly banned bump stocks after the 2017 mass shooting at a Las Vegas concert that was the deadliest in U.S. history. In the ensuing years, gun rights groups challenged the underlying rationale that bump stocks are effectively machine guns — culminating in a legal fight now before the Supreme Court. 

Justice Brett Kavanaugh, a conservative who often sits at the ideological center of the court, is raising concerns about people being prosecuted under the ban without even knowing it exists.

"Even if you're not aware of the legal prohibition, you can be convicted," Kavanaugh pressed the attorney representing the Biden administration. "That's going to ensure a lot of people who were not are of the legal prohibition."