Second Amendment advocates are pursuing multiple lawsuits against gun-control measures in an effort to trigger a Supreme Court challenge that could upend decades of legislation.

The Second Amendment Foundation has filed multiple gun-rights challenges in federal courts across the country. Founder Alan Gottlieb said the muddled nature of state laws, on issues ranging from open carry to the possession of certain weapons, calls out for judicial review from the nation's highest court.

"Politicians making claims that the Second Amendment doesn't apply to so-called assault weapons is exactly why the Supreme Court needs to take all of these cases and put this issue to rest," Gottlieb told the Washington Free Beacon.

The Supreme Court has never heard a legal challenge on either federal or state bans on "assault weapons" and has been largely silent on Second Amendment issues since its landmark rulings in District of Columbia v. Heller (2008) and McDonald v. Chicago (2010)—a pair of decisions that struck down strict gun-control laws in Washington, D.C., and Illinois. Gun-control activists have used the silence from the justices as approval for new bans and confiscation measures. Virginia delegate Mark Levine (D.) told the state Senate Judiciary Committee in February that the constitutionality of his proposed "assault weapons" ban and magazine confiscation proposal was settled law.

"I understand that some people might disagree with the policy here but there should be no question as to the constitutionality of this bill," Levine said.

The Virginia Senate ultimately voted against Levine's legislation, but gun advocates say that his rhetoric demonstrates why the Supreme Court should weigh in.

If the Supreme Court is moved to rule on new gun-rights cases—especially the legality of bans like Levine's—it could change the landscape of gun laws in the United States. Any ruling expanding protections for what categories of guns Americans have a right to own, or where they have a right to take their guns, could strike down laws in heavily Democratic states such as California, New York, and Illinois.

In 2016, the Supreme Court used Heller to toss out a Massachusetts woman's conviction for possessing a stun gun banned in the state—the ban was later struck down by the Massachusetts Supreme Judicial Court. That was the only major gun-rights case that the justices ruled on in the last decade. Gun-rights advocates say the reluctance of the High Court to act has led to a confusing web of lower court decisions that leave the extent of Second Amendment protections an open question.

"There's confusion across the country on this because of different rulings on it," Philip Van Cleave, head of the Virginia Citizens Defense League, said. "They absolutely should come in and get this straightened out once and for all so this right is protected."

Second Amendment activists are confident that they would prevail if state or local gun bans reach the Supreme Court. The Court ruled in Heller that weapons "in common use" for lawful purposes are protected by the Second Amendment. The AR-15 and other semiautomatic rifles are some of the most popular guns in the country with more than 17.7 million owned by civilians in the United States, according to a recent industry estimate.

"Under the U.S. Supreme Court’s Second Amendment precedent, Gov. Northam’s proposed gun ban is flat-out unconstitutional," NRA spokeswoman Catherine Mortensen said. "The highest court in the land has repeatedly ruled that banning commonly owned arms violates the Second Amendment."

Appellate courts have disagreed, but there has been no uniform legal reasoning between circuits affirming the constitutionality of gun bans.

The Seventh Circuit ruled AR-15s and similar firearms banned in Cook County, Illinois, do not have a "reasonable relationship to the preservation or efficiency of a well-regulated militia." The Fourth Circuit ruled the AR-15s banned by Maryland are "‘weapons that are most useful in military service' — which the Heller Court singled out as being beyond the Second Amendment’s reach." The D.C. Circuit ruled there was a "substantial relationship" between the city's AR-15 ban "and the objectives of protecting police officers and controlling crime." The First Circuit ruled Massachusetts "(at most) minimally burdens" Second Amendment rights with its AR-15 ban.

Mark Oliva, a spokesman for the National Shooting Sports Foundation, said the varied opinions make the issue ripe for the Supreme Court to take up.

"There are no grounds to say it's settled law. You have circuit courts of appeal that are at disagreement as to why those bans are constitutional," he told the Free Beacon. "When you have disagreement among the circuit courts that is a reason why the Supreme Court could be weighing in to come to an agreement on what that standard is."

Levine, the Virginia Democrat, argued that gun-control bans have received the blessing of the Roberts Court. He pointed to the Supreme Court's decision not to take up an appeal of the Fourth Circuit ruling upholding Maryland's assault-weapons ban.

"This weapons restriction is clearly constitutional," he told the state Senate in February. "The [Maryland] case was appealed to the United States Supreme Court. The United States Supreme Court denied certiorari. That wasn't the first time they've declined to review such a case. They've done so in other cases."

Gun-rights advocates pointed out that the Supreme Court deciding not to hear an appeal is not tantamount to endorsing the lower court's decision. There are many reasons the Court might decide not to take a case, from limited docket space to justices waiting for split rulings at the circuit level, or simply wanting a better test case on an issue.

"I think Delegate Levine's arguments are probably the best defense of his gun-confiscation legislation that he could make, but they don't stand up to legal precedence on why the Supreme Court does or does not take a case," Gottlieb said.

There are at least six separate gun-rights challenges from Maryland, Illinois, Massachusetts, California, and New Jersey—as well as one challenging a federal ban on interstate handgun sales—waiting for review by the High Court. Not every gun-control advocate shares Levine's optimism. Ladd Everitt, former director of the gun-control group One Pulse for America, said pro-gun control policymakers should not give the Supreme Court leeway to set new precedents overturning gun-control laws.

"The majority’s decision in Heller led to a torrent of litigation against gun-control laws nationwide," Everitt said in a 2019 op-ed. "Thankfully, federal courts have rejected most of those challenges. It will become harder to do so in the future, however, if our increasingly pro-gun Supreme Court is allowed additional, unnecessary bites at the Second Amendment apple."

The District of Columbia declined to appeal a 2017 decision striking down its restrictive gun-carry permit law because city officials feared a Supreme Court decision would strike down similar laws in other states. In 2019, New York City officials attempted to withdraw a bid to defend a law limiting the transportation of legally owned firearms after the Supreme Court agreed to review the case. Local gun-control groups even lobbied for a state law loosening the travel restrictions out of fear of what the Court might rule.

Several Supreme Court justices have publicly spoken out in favor of the Court taking more gun-rights cases. When the Court declined to hear a challenge to a California gun-carry law in 2017, Justices Clarence Thomas and Neil Gorsuch wrote a dissent, telling their colleagues not to "stand by idly while a State denies its citizens that right."

"The Court's decision to deny certiorari in this case reflects a distressing trend: the treatment of the Second Amendment as a disfavored right," Thomas said. "The Court has not heard [an] argument in a Second Amendment case in over seven years—since March 2, 2010, in McDonald…. Since that time, we have heard argument[s] in, for example, roughly 35 cases where the question presented turned on the meaning of the First Amendment and 25 cases that turned on the meaning of the Fourth Amendment."

The make-up of the Court has changed drastically since McDonald, following the additions of President Trump's appointees, Brett Kavanaugh and Neil Gorsuch. Kavanaugh has previously weighed in on the constitutionality of gun bans, notably dissenting when the D.C. Circuit upheld the city's assault-weapons ban in 2011.

"In my judgment, both D.C.'s ban on semiautomatic rifles and its gun registration requirement are unconstitutional under Heller," he wrote. "There is no meaningful or persuasive constitutional distinction between semiautomatic handguns and semiautomatic rifles. Semiautomatic rifles, like semiautomatic handguns, have not traditionally been banned and are in common use by law-abiding citizens for self-defense in the home, hunting, and other lawful uses."

Americans may soon get a preview of which direction the current Court will move on guns when it issues its decision in the New York City gun-transportation case. In December, justices heard oral arguments in the New York City case and will decide whether to allow authorities to drop the case or rule on the merits. No matter the outcome in that case, both sides of the gun-control debate say the Supreme Court has the potential to shake up the entire course of legislative debates moving forward.