A coalition of 20 Republican attorneys general requested the U.S. Court of Appeals to reverse a Delaware district court decision upholding bans on “assault weapons” and large capacity magazines (LCMs).

The coalition, led by Montana Attorney General Austin Knudsen (R.), filed the amicus brief Monday to support the Delaware State Sportsmen’s Association (DSSA) in their case against the bans. The DSSA has argued that two Delaware bills violate the Second Amendment. The bills impose bans on over 40 semi-automatic “assault long guns,” 19 semi-automatic “assault pistols,” copycat weapons, and magazines capable of holding more than 17 rounds of ammunition.

“Because HB 450 and SS 1 both regulate conduct covered by the ‘plain text’ of the Second Amendment—’keep[ing] and bear[ing] Arms,’ see U.S. Const. amend. II—they are presumptively unconstitutional,” the attorneys general wrote in their brief. “To justify HB 450 and SS 1, Delaware ‘must demonstrate that the regulation is consistent with this Nation’s historical tradition of firearm regulation.'”

The brief heavily cites last year’s Supreme Court case New York State Rifle and Pistol Association v. Bruen, which has led to the demise of numerous gun restrictions nationwide. Over a year after the Bruen decision, more than 30 gun-rights claims have already succeeded in federal court, including several against “assault weapons” bans in other states. Knudsen and the coalition argue that Delaware’s imposed bans on “assault weapons” and LCMs do not align with the historical understanding of the Second Amendment required by Bruen. In the brief, the all-Republican coalition argued that while previous laws had attempted to limit the use of specific weapons, an analogous total ban on popular firearms was never imposed near the Founding Era. They said that means there is no precedent to support the bans in question.

“Nearly all of the historical regulations that the district court relied on stop short of complete bans, and instead tailored their prohibitions to minimize the criminal use of certain dangerous and unusual weapons,” the coalition wrote. “But HB 450 and SS 1 go farther and impose complete bans on so-called assault weapons and LCMs, so they are not ‘relevantly similar’ to the proposed historical analogues.”

The attorneys general also argued that “the district court failed to engage in the nuanced analogical inquiry” Bruen requires.

“When evaluating ‘cases implicating unprecedented societal concerns or dramatic technological changes,’ Bruen’s analogical inquiry requires ‘a more nuanced approach,'” the brief says. “And because the Second Amendment’s ‘meaning is fixed according to the understandings of those who ratified it,’ that nuanced approach still requires that the ‘government identify a well-established and representative historical analogue.'”

The attorneys general said the district court’s ruling acted as a “regulatory blank check” and thus ran afoul of Bruen’s requirements. They said, “The district court found that HB 450 and SS 1 were ‘comparably justified’ by improperly smuggling in the interest-balancing, means-end analysis that Bruen rejected.”

Delaware Governor John Carney (D.) signed the gun-control measures just over a year ago, in June 2022. DSSA filed its lawsuit challenging the bills in September. By April, U.S. District Court Judge Richard Andrews rejected DSSA’s request for a preliminary injunction while considering the case. That led to this week’s appeal.

Governor Carney signed the bills less than a month after the tragic mass shooting in Uvalde, Texas. The coalition called this “understandable” but still deemed the complete ban unconstitutional.

“No doubt HB 450 and SS 1 were motivated by an understandable concern with the recent rise in mass shooting incidents, but they are inconsistent with this Nation’s historical tradition of regulating dangerous and unusual weapons,” the attorneys general wrote.

Attorneys general from Alabama, Arkansas, Georgia, Idaho, Indiana, Iowa, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, New Hampshire, North Dakota, South Carolina, South Dakota, Utah, Virginia, West Virginia, and Wyoming joined Knudsen in signing onto the brief.