To Hunter Biden’s father, the Supreme Court decision last June that expanded Second Amendment rights is a travesty for gun control.
But to Hunter Biden’s lawyers, it has been an opening.
In the months after the court’s landmark ruling that gave people a broad right to carry guns outside the home, Mr. Biden’s lawyers told Justice Department prosecutors — who were investigating whether to charge him in connection with a gun purchase — that a prosecution of him would likely be ruled moot, according to two people briefed on the matter.
While it is not uncommon for defense lawyers to point to shifting precedents to stave off prosecution, the circumstances of this argument, like so many elements of the Hunter Biden saga, are striking: A president’s son is invoking a court decision his father has described as an affront to “common sense and the Constitution” — and staking that claim on a majority opinion written by Justice Clarence Thomas, a vigorous supporter of gun rights whom many Democrats see as having helped enable the gun lobby.
The U.S. attorney in Delaware, David C. Weiss, is wrapping up his investigation into Hunter Biden as uncertainty mounts about the legality of many gun laws after the court’s landmark ruling last summer, which has led to a wide-ranging assault on existing firearms laws.
Mr. Biden is under investigation for several potential offenses, including whether he had lied on a federal firearms application in 2018 when asked if he was addicted to drugs. His lawyers, including the white-collar defense lawyer Christopher Clark, have argued that any charge against him would likely be thrown out after federal appeals courts rule on two major challenges that cite the Supreme Court decision as precedent.
It is unclear if Mr. Weiss is receptive to that suggestion. A spokeswoman for Mr. Weiss did not immediately respond to a request for comment.
One case the Hunter Biden team has cited is a challenge to the criteria used in the federal firearms background check system, which relies on a ubiquitous application known as a 4473 form, pending before the U.S. Court of Appeals for the Third Circuit, which includes Delaware. In that case, Bryan David Range, a Pennsylvania man who was denied a gun permit over a decades-old misdemeanor, is asking to be granted gun ownership based, in part, on Justice Thomas’s opinion.
That case, argued in February, is likely to be decided over the next several months.
Hunter Biden’s lawyers have relied on the argument as they have asserted that the long-running Justice Department investigation, which has examined an array of matters, including his failure to file federal income taxes, should end with no charges. In recent years, the investigation expanded to include scrutiny of his purchase of a handgun in 2018, and his false response of “no” when asked whether he was an “unlawful user” of drugs. At the time, Mr. Biden was struggling to remain sober.
But such federal prosecutions are relatively rare, and seldom pursued as stand-alone charges. And officials at the Bureau of Alcohol, Tobacco, Firearms and Explosives responsible for reviewing Mr. Biden’s file were skeptical of bringing charges against him, especially considering that he had sought treatment and had no prior criminal history, according to another person with knowledge of the situation.
There have been calls in recent years to alter or remove the drug question from the firearms application, especially when it comes to marijuana, but Congress has not amended federal firearms or drug laws, and federal officials have not weakened their regulations.
On Tuesday, the A.T.F. held firm on that position, warning cannabis users in Minnesota they were barred from buying guns or ammunition despite the easing of state restrictions.
The case before the Third Circuit — which has drawn national attention — challenges the government’s right to block people convicted of nonviolent crimes or other “nonserious” violations from owning a firearm. (Mr. Range’s offense was misrepresenting his income to obtain food stamps.)
At the center of the case, as in the Hunter Biden investigation, is the 4473 form, “a gotcha trap intended to deny people their Second Amendment rights,” said Michael P. Gottlieb, Mr. Range’s lawyer.
“This is a case of national importance,” he said. “Whatever the Third Circuit decides, I see this going all the way up to the Supreme Court.”
Justice Department lawyers have said that nonviolent offenses indicate a person’s general “disrespect for rule of law” and should bar them from gun ownership.
But the Supreme Court’s ruling has spawned dozens of lawsuits across the country, including some that challenge the federal government’s right to deny firearms to people who are addicted to drugs. The most significant decision to date came in February when a three-judge appeals panel in New Orleans struck down part of a federal law that banned people under domestic violence restraining orders from owning firearms.
Most of the cases are based on a broad standard established in Justice Thomas’s majority opinion, which asked that gun laws be “consistent with this nation’s historical tradition of firearm regulation.”
Another case Mr. Biden’s team has cited is a February ruling from a Federal District Court in Oklahoma that struck down parts of a federal law prohibiting marijuana users from owning firearms. The Justice Department is expected to appeal the decision.