Shortly after Hunter Biden was indicted on three gun-related federal charges, his attorney made it clear that his multi-pronged defense strategy in the historic case would include questioning the legality of the gun control accusation at the heart of the matter.

"The constitutionality of these charges are very much in doubt," Abbe Lowell, a central figure of Hunter Biden's legal team, told CNN's Erin Burnett on "OutFront."

The doubts can be directly traced to a major Second Amendment ruling last year penned by conservative Justice Clarence Thomas that has made it easier to strike down gun control laws. Thomas said that going forward the government "may not simply posit that the regulation promotes an important interest," instead, he said the judges must look to text and history when deciding whether a law passes muster.

"Only if a firearm regulation is consistent with this Nation's historical tradition may a court conclude that the individual's conduct falls outside the Second Amendment's 'unqualified command,'" Thomas wrote in the 6-3 decision of New York State Rifle & Pistol Association v. Bruen.

Though the decision was harshly criticized by President Joe Biden and other supporters of stricter gun laws, it might ultimately give his son a legal avenue as the younger Biden tries to fend off the first-ever criminal conviction of a president's son or daughter.

Already, the 5th US Circuit Court of Appeals has used Thomas' decision to declare unconstitutional the gun possession law at the heart of Hunter Biden's case. And the Supreme Court in November will hear a related case that grapples with who can be barred from owning a firearm.

"Justice Thomas' position in Bruen is a position that excites gun rights activists and disappoints gun regulation proponents. But it's also a position that potentially benefits many criminal defendants, even criminal defendants like Hunter Biden," said Benjamin Levin, a law professor at Washington University in St. Louis and expert on US gun laws.

Biden was charged earlier this month by special counsel David Weiss with three gun-related charges: two concerning false statements he made on federal firearms form and one that prohibits unlawful users of controlled substances from possessing a firearm.

He has told a federal judge he plans to plead not guilty to the charges when he is arraigned next week.

Generally speaking, the 5th Circuit's decision last month in US v. Daniels means that other defendants convicted under the law within that circuit's jurisdiction -- Louisiana, Texas and Mississippi -- could seek to challenge their convictions under the new ruling.

Though Delaware, the state where Weiss brought the charges, isn't within the 5th Circuit, legal experts told CNN that the case and the larger conservative push to implement an expansive view of the Second Amendment's protections nationwide could still represent one of the better legal defenses Hunter Biden's lawyers are able to make.

"It's their duty to defend him as well as possible. And if this is the best precedent out there with which to defend him then they have a duty to attempt to use that to their client's advantage," said George Mocsary, a Second Amendment expert and law professor at the University of Wyoming.

"And Daniels is, I would say, among the better things out there with which they can defend their client. That doesn't mean it's strong, but it certainly doesn't hurt them," he added.

In the 5th Circuit case, the defendant, Patrick Daniels, was seeking to throw out his 2022 conviction under the same federal gun possession law Hunter Biden is facing. Daniels, who is a frequent marijuana user, according to court filings, successfully argued to the court that the law is at odds with the Supreme Court's Bruen ruling.

"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 a unanimous three-judge panel. "Nor do more generalized traditions of disarming dangerous persons support this restriction on nonviolent drug users."

Hunter Biden's case and Daniels' case differ in a variety of ways, but Hunter Biden's attorneys can still use the ruling and the legal arguments made in that case to argue that the law is also unconstitutional as applied to their client in requests to get the charges dropped or on appeal if he is convicted in the case.

While buying a revolver at a Delaware gun shop in 2018, Hunter Biden allegedly lied on a federal form when he swore that he was not using, and was not addicted to, any illegal drugs -- even though he was struggling with crack cocaine addiction at the time of the purchase.

"The (appeals) court is saying the law is unconstitutional as applied to a frequent user of marijuana. But I don't think that the reasoning in the case, the way that the court looks at the history, necessarily limits that holding to marijuana," said Andrew Willinger, the executive director of the Duke Center for Firearms Law. "The court seems to be saying more broadly that there is no historical analog for banning possession based on sort of non-contemporaneous drug use."

"So I read that decision to certainly open the door to a challenge in a case like Hunter Biden, where I'm not aware that there's any proof ... of gun possession while under the influence," Willinger said.

Apart from the factual differences between the two cases, Biden's attorneys also face an uphill battle with their use of Daniels, Mocsary explained, because any appeal from the Delaware court would go to the 3rd Circuit -- which covers Delaware, New Jersey and Pennsylvania -- not the 5th.

But a number of district courts have upheld the gun possession law since Bruen, Willinger noted, explaining that the differing rulings inject "substantial uncertainty" into the legality of the statute and further underscore how it's on shaky legal ground a little over a year after the high court's ruling in Bruen.

"It's not like this is a silver bullet that this is, you know, certainly going to succeed," he said. "But (it's) definitely a viable argument."

The president was clear last year that he opposed the conservative majority's decision in Bruen, and his Justice Department had worked to defend the New York gun law at the center of the case.

Biden said at the time that he was "deeply disappointed" in the ruling, which, he said, "contradicts both common sense and the Constitution, and should deeply trouble us all."

The limits of Bruen will be tested later this term when the justices examine a federal law that bars an individual subject to a domestic violence restraining order from possessing a firearm, in a case that could have salience for Hunter Biden's attorneys.

The appeals court decision in US v. Rahimi, the case before the justices, was cited heavily by the panel that issued the decision in Daniels last month.

Rahimi will represent the first time the court has reexamined its decision in Bruen since 2022, potentially setting up a second key ruling related to firearms from the conservative-majority court in recent years.

"I think that if I were Biden's attorney, I would find myself rooting for more expansive Second Amendment decisions," Levin said. "The reality of being a defense lawyer in one of these settings is you're looking for more case law that possibly bolsters your side's case and that's going to be more pro-defendant Second Amendment cases."