A federal judge said Wednesday that federal prohibitions on licensed dealers selling handguns to 18- to 20-year-olds are unconstitutional, in what is the latest legal volley over age-based firearm regulations -- a court fight that has escalated since the Supreme Court's major Second Amendment ruling last year.

US District Judge Robert Payne of the Eastern District of Virginia said that under the test laid out in the Supreme Court's recent ruling, the federal regulation runs afoul of the Second Amendment.

"Because the statutes and regulations in question are not consistent with our Nation's history and tradition, they, therefore, cannot stand," he wrote, referencing the Supreme Court ruling's instruction that lower courts look to the gun regulations that were in effect during the Constitution's framing to decide whether a current gun law violates the Second Amendment.

The Justice Department declined to comment. But its attorneys have the option to ask that Payne's ruling be paused for it to be appealed. There are also procedural questions about the case that must be settled before Payne issues a mandate that puts the ruling into effect.

In his opinion, Payne concluded that 18-to 21-year-olds were part of the American political community -- citing the age group's ability to vote and enlist in the military -- and thus the age group fell under the Second Amendment's protections.

"If the Court were to exclude 18-to-21-year-olds from the Second Amendment's protection, it would impose limitations on the Second Amendment that do not exist from other constitutional guarantees," Payne, a George H. W. Bush-appointee, wrote.

He then turned to the second part of the Supreme Court's test, where the high court said that a regulation could only be upheld if analogous regulations existed at the time of the framing.

"The Government has not presented any evidence of age-based restrictions on the purchase or sale of firearms from the colonial era, Founding, or Early Republic," Payne said.

He later concluded that the "lack of analogous regulations permits a finding that the Founders considered age-based regulations on the purchase of firearms to circumscribe the right to keep and bear arms confirmed by the Second Amendment."

Even before the 2022 Supreme Court's ruling, known as New York State Rifle & Pistol Association, Inc. v. Bruen, the constitutionality of gun restrictions for older teenagers was a flashpoint of firearm litigation and federal courts have taken different approaches to the question. Those in favor of gun safety laws have pointed to the prevalence of mass shootings perpetrated by shooters in their late teens, while opponents of gun restrictions for 18-to-20-year-olds have argued that teenage participation in militias at the timing of the founding puts the constitutionality of such laws in questions.

Last year's Bruen opinion -- authored by Justice Clarence Thomas and joined by the high court's other GOP-appointees -- put these legal battles on overdrive. The new opinion from Payne hints at what could be a major dispute that the Supreme Court must ultimately resolve.

In March, the 11th US Circuit Court of Appeals upheld a Florida law -- passed after the massacre at Marjory Stoneman Douglas High School -- that raised the minimum age to purchase a gun from 18 to 21. (Federal trial courts in Virginia sit under the 4th US Circuit Court of Appeals, and as such are not bound by 11th Circuit precedents.) In concluding the Florida ban was constitutional, the 11th Circuit opinion pointed to similar restrictions that were in place in the mid-1800s, around the time of the ratification of the 14th Amendment, which extended the Second Amendment's protections to states.

Payne acknowledged Wednesday he was taking a different approach than that of the 11th Circuit. He noted because his case concerned a federal restriction rather than a state law, he was looking at the gun regulations in place at the country's founding, in the late 18th century, when the Second Amendment was adopted. Whether the 11th Circuit had a "sound" rationale in relying instead on Reconstruction-era regulations "will be tested on appeal," Payne said in a footnote.

In an earlier case, the 4th Circuit said in 2021 that the federal regulations setting a minimum age of 21 years old for purchasing handguns from licensed dealers violated the Second Amendment. However, after the challengers in that case turned 21, the appeals court ruled that the lawsuit was moot and vacated that opinion.

To get around that issue, the challengers in the latest lawsuit are seeking class certification. The judge has asked for the parties to weigh in next week on how to move forward with that question.

Elliott Harding, a lawyer for the challengers, said in a statement that they were "pleased" the court ruled in their favor Wednesday "in such a well-written and thorough decision."

"Even though it ensures that future buyers can now purchase these firearms in the federal system, one that includes background checks and other requirements, we expect that the defendants will appeal," the statement said, alluding to the unregulated, private market that older teenagers currently use to purchase handguns. "Nevertheless, we remain optimistic the decision will be affirmed in due course."