Washington — Less than a year after the Supreme Court issued its major decision expanding gun rights, the new legal test laid out by Justice Clarence Thomas in his majority opinion has reshaped the legal landscape for firearms laws and led to uncertainty over whether measures that aim to curb gun violence can survive legal scrutiny.

The laws — those recently enacted in the states, as well as longstanding federal restrictions with broad support — are being tested in courtrooms from coast to coast, where judges are tasked with evaluating whether they are “consistent with the nation’s historical tradition of firearm regulation.”

“We’re seeing a lot of action and a lot of unpredictability when it comes to the Second Amendment after Bruen,” said Joseph Blocher, co-director of Duke University’s Center for Firearms Law. “It’s happening in a bunch of different directions, and the source of the change is the new methodology that the Supreme Court announced in the Bruen case because it instructs courts to evaluate the constitutionality of laws based solely on whether they are in some ill-defined sense consistent with history”

Under the Supreme Court’s new standard for determining whether gun laws are within constitutional bounds, the government is required to show that the measure is consistent with the nation’s historical tradition of gun regulation.

“We hold that when the Second Amendment’s plain text covers an individual’s conduct, the Constitution presumptively protects that conduct,” Thomas wrote. “To justify its regulation, the government may not simply posit that the regulation promotes an important interest. Rather, the government must demonstrate that the regulation is consistent with this Nation’s historical tradition of firearm regulation. “

The decision, which struck down a New York handgun licensing law, prompted the governors of New York and New Jersey to enact new firearms restrictions, and Illinois Gov. J.B. Pritzker signed into law last month a measure that bans the sale and distribution of assault weapons and high-capacity magazines in the state.

But the new requirements have been swiftly met with a flood of lawsuits from gun rights organizations and firearms owners who argue they do not pass constitutional muster under the Supreme Court’s Bruen decision. And federal judges navigating the changed legal landscape have cited the June ruling in their own decisions, many blocking enforcement of the gun laws.

“For the vast majority of America historically and until June of last year, the overwhelming obstacle to gun regulation has been political. It has not been the case that courts are actively striking down gun laws, it’s that they’re not being passed in the first place,” Blocher said. “After Bruen, we’re seeing a more active role for courts. But there’s still absolutely room even under the most restrictive reading of Bruen to pass common-sense gun regulations that the vast majority of Americans favor.”

Signed into law days after the Supreme Court’s Second Amendment decision, New York’s new rules requires concealed carry applicants to demonstrate “good moral character” and bans firearms in some “sensitive” spaces like places of worship, bars, and public parks. Six gun owners in New York and the New York State Rifle and Pistol Association challenged provisions of the law, arguing it was unconstitutional.

A federal district court in Syracuse, New York, blocked provisions of the law from being enforced after drawing on the framework set forth in the Bruen decision, but the 2nd Circuit allowed them to go into effect. The gun owners asked the Supreme Court to intervene, but the court declined, leaving the law in place while proceedings continue.

Similar to New York’s restrictions, the New Jersey law criminalizes carrying handguns in certain sensitive places, including public libraries and museums, bars and restaurants, and on private property. Gun owners and four gun organizations challenged provisions of the law, and last month, a federal district court judge halted enforcement of the sensitive-place rules.

“The state may regulate conduct squarely protected by the Second Amendment only if supported by a historical tradition of firearm regulation,” U.S. District Judge Renee Bumb wrote. “Here, Plaintiffs have shown that Defendants will not be able to demonstrate a history of firearm regulation to support any of the challenged provisions.”

While the court fights in New Jersey and New York have involved new laws enacted in response to the Supreme Court’s decision, the new legal test set forth by the high court puts federal laws that predated the ruling in jeopardy.

In a case involving a West Virginia man who was charged in May for unlawfully possessing a firearm with an obliterated serial number, U.S. District Judge Joseph Goodwin found the law to be unconstitutional and dismissed the charge.

“A firearm without a serial number in 1791 was certainly not considered dangerous or unusual compared to other firearms because serial numbers were not required or even commonly used at that time,” he wrote.

Last week, a three-judge panel on the U.S. Court of Appeals for the 5th Circuit ruled a 30-year-old federal law that prohibits a person subject to a domestic violence restraining order from possessing firearms is unconstitutional in light of the Bruen decision.

“The government fails to demonstrate that [the statute’s] restriction of the Second Amendment right fits within our Nation’s historical tradition of firearm regulation,” Judge Cory Wilson wrote for the panel. The law is an “outlier that our ancestors would never have accepted,” he concluded, citing Thomas’s opinion.

Attorney General Merrick Garland indicated the Justice Department will appeal the ruling. It could ask the full 5th Circuit to rehear the case or seek review by the Supreme Court.

Blocher, of Duke’s Center for Firearms Law, said prohibitions like the domestic violence gun law are regarded today as “valid and even essential.”

“In the founding era, you won’t always find laws that directly disarmed people for intimate-partner violence,” he said. “It wasn’t something legislatures concerned themselves with, but it would be absurd to say we can’t do that today simply because in 1791 women were not given the protection of law that they deserved then and now.”

While some gun measures, such as so-called “red flag laws” that allow courts to issue temporary orders authorizing law enforcement to seize firearms from individuals who are seen as threat to themselves or other people, have bipartisan support, the Bruen decision could pave the way for legal challenges to those laws, too.

District court judges have struggled in their efforts to apply the Supreme Court’s Bruen decision, particularly when assessing whether a firearm regulation is consistent with the nation’s historical tradition, said Esther Sanchez-Gomez, litigation director for Giffords Law Center.

“It invites district courts to become historians in ways they’re not equipped to be,” she told CBS News. “It also requires this in-depth review of the historical record, which is an onerous task, even for an expert, and district courts with heavy dockets are not well-positioned to be taking that on.”

The challenge for judges in applying the new so-called “historical tradition” test spilled into public view in October, when U.S. District Judge Carlton Reeves issued an order raising the possibility of appointing a historian to serve as a “consulting expert” in a case challenging the constitutionality of a federal statute prohibiting felons from possessing firearms.

“This Court is not a trained historian. The Justices of the Supreme Court, distinguished as they may be, are not trained historians. We lack both the methodological and substantive knowledge that historians possess,” he wrote. “The sifting of evidence that judges perform is different than the sifting of sources and methodologies that historians perform. And we are not experts in what white, wealthy, and male property owners thought about firearms regulation in 1791. Yet we are now expected to play historian in the name of constitutional adjudication.”

Many of the court fights over new state gun controls are in the early stages, and judges have been asked to block enforcement of the laws while legal proceedings continue.

Still, their struggles in applying the Supreme Court’s new legal test and recent decisions invalidating new and existing laws loom over state and federal efforts to enact more gun controls. But advocates of more stringent gun laws say the prospect of legal battles should not be a deterrent for lawmakers.

“Legislators should be taking Justice Thomas at his word and understand that Brue is not a regulatory straightjacket,” Sanchez-Gomez said. “Doing nothing in the wake of the violence out of fear it might be challenged seems like a game of negotiating with yourself at the cost of many lives. Let’s talk about Bruen, understand what it means, but given that it’s still in flux, it’s counterproductive to be thinking too much about exactly the outer bounds.”