The US Supreme Court ruled unanimously Thursday that a habitual user of marijuana cannot be barred from owning a gun.

The 9-0 ruling is a victory for supporters of the Second Amendment to the US Constitution, which says Americans have the right to keep and bear arms.

The case before the court involved Ali Hemani, a Texas man who was indicted for being unlawfully in possession of a Glock pistol after admitting that he used marijuana about every other day.

An appeals court ruled that barring Hemani, a dual US-Pakistani national, from owning a gun violated his Second Amendment rights.

Republican President Donald Trump's Justice Department, which generally backs expansive gun rights, challenged that decision.

The Supreme Court sided with the appeals court and ruled that the prosecution of Hemani is "inconsistent with the Second Amendment."

Justice Neil Gorsuch, who authored the opinion, noted that marijuana laws have been relaxed in recent years across much of the country.

"Whatever one thinks of these developments, the federal government has not just tolerated them; it helped fuel them," Gorsuch said.

"All of which leaves it awkwardly positioned to suggest that the millions of Americans who now regularly use marijuana are categorically and unusually dangerous."

At the same time, Gorsuch stressed that the decision is "narrow," focusing on marijuana, and does not address efforts to ban addicts of other types of illegal drugs from owning firearms.

Former president Joe Biden's son Hunter was convicted under the statute, which prohibits the possession of firearms by a person who is "an unlawful user of or addicted to any controlled substance." It is punishable by up to 15 years in prison.

Hunter Biden was pardoned by his father shortly before he left office last year.

The Supreme Court's ruling in the Hemani case was welcomed by Cecillia Wang, legal director at the American Civil Liberties Union.

"Today's unanimous 9-0 decision makes it clear that the government cannot make it crime for people to own a gun, which the Supreme Court has held is a fundamental constitutional right, simply because they use marijuana," Wang said.

"With nearly half of Americans reporting marijuana use at some point in their lives, this ruling protects the rights of millions and curbs the government's ability to impose arbitrary and discriminatory penalties," she added.

The Hemani case is one of two gun rights cases the court heard this term.

The other involved a Hawaii law restricting where holders of concealed carry permits can bring their firearms. The court is yet to rule on that case.

The Supreme Court recently upheld regulation of "ghost guns" -- firearms sold in easy-to-assemble kits -- and restricted gun access for persons subject to domestic violence restraining orders.