Since the horrific murders at Sandy Hook Elementary a decade ago, America has seen hundreds more mass shootings, a sharp rise in gun deaths generally, and an alarming turn toward gun-glorifying political extremism. Yet we still depend on hundreds of laws that keep guns out of crowded public places, stop teenagers from buying handguns, and prohibit criminals from arming themselves with assault rifles. Now, because of a recent Supreme Court ruling, many of these remaining regulations are in danger of being dismantled. As bad as America’s gun-violence problem is, it could be about to get much worse.

Less than two years after the appointment of President Donald Trump’s third pick for the U.S. Supreme Court created a 6–3 conservative supermajority, Justice Clarence Thomas wrote the majority opinion in the case New York State Rifle & Pistol Association, Inc. v. Bruen. The Court could have issued a narrow decision and directed New York to be more lenient in issuing concealed-carry permits. But as in the Dobbs v. Jackson decision on abortion, which came a day after Bruen this year, the conservative majority seized an opportunity not to adjust precedent incrementally, but to destroy it completely.

For public safety and gun policy, the Bruen opinion is proving nothing short of seismic. Even as the nation struggles with yet another series of mass shootings, courts across the country are rushing to deal with a spate of lawsuits and motions that will create regulatory chaos over firearms. Many of these cases are tailored to produce appeals that may ultimately go up to a Supreme Court predisposed to the broadest possible interpretations of Second Amendment rights.

In the Bruen opinion, Thomas made clear that, henceforth, the Court’s conservative majority would judge all firearms regulations by a new originalist standard: If there is no historical proof of a gun law linked to 1791 or 1868—the years when the Second and Fourteenth Amendments, respectively, were ratified—then any modern law restricting firearms is liable to be ruled unconstitutional. Never mind that any teenager with a modern AR-15 rifle can fire several times every second, whereas a well-trained 18th-century soldier could fire a musket, at best, three or four times a minute.

An effect of the Thomas opinion is to press judges in lower courts into serving as historians and archival researchers. To decide new gun cases, they must go searching for precedents among incomplete or nonexistent records, some of which are centuries old and difficult to decipher. The results are likely to shock Americans who rely on long-established public-safety laws to protect children in schools and citizens who gather in churches or attend sports events and the like. Instead of making it more difficult for a troubled 18-year-old to become a deadly mass shooter, this Court has made it much easier—all in the cause of empowering an unrepresentative, radical pro-gun minority of Americans whose vocal demands about their right to bear arms have found sympathetic ears on the Supreme Court.

Several cases already give us a glimpse of the future under Bruen. In West Virginia, a judge recently ruled unconstitutional the federal law that mandates serial numbers on guns, because he can find no evidence of a statute requiring firearms to carry a serial number dating to 1791. If that judge’s decision is upheld, police detectives will find it almost impossible to solve gun crimes, because serial-number records are the basis for most such investigations.