A federal appeals court on Wednesday struck down a decades-old law barring users of illegal drugs from possessing firearms -- the latest blow to US gun regulations after the Supreme Court cleared the way last year for courts to reexamine the nation's gun laws under a new legal standard.

In a unanimous judgement from a three-judge panel at the New Orleans-based appeals court, the court said the 1968 law is unconstitutional, citing a landmark 2022 Supreme Court decision that changes the framework that lower courts must use when analyzing gun restrictions.

"In short, our history and tradition may support some limits on an intoxicated person's right to carry a weapon, but it does not justify disarming a sober citizen based exclusively on his past drug usage," Circuit Judge Jerry Smith, a Ronald Reagan appointee, wrote for the panel. "Nor do more generalized traditions of disarming dangerous persons support this restriction on nonviolent drug users."

The ruling means that the man who brought the challenge to the regulation, Patrick Daniels, will have his July 2022 conviction under the law thrown out. Daniels had been sentenced to nearly four years in prison and three years of probation.

"As applied to Daniels, then, (the federal gun law) violates the Second Amendment," Smith wrote.

The judgment also means that other defendants convicted under the law within the Fifth Circuit Court of Appeals' jurisdiction could seek to challenge their convictions under the new ruling. The circuit covers Louisiana, Texas and Mississippi.

Daniels had been arrested in April 2022 after law enforcement officers searched his car during a stop and found marijuana butts and two loaded firearms. The officers did not administer a drug test the night of the stop, but Daniels admitted that he was a frequent user of marijuana.