A district court’s invalidation of the entire Affordable Care Act was an egregious misuse of judicial power, Democratic lawmakers and state attorneys general told the Fifth Circuit on Wednesday, setting the stage for oral arguments on the ACA’s fate.

In a pair of reply briefs, the Democratic-controlled U.S. House of Representatives and a coalition of Democratic attorneys general portrayed a Texas federal judge’s nullification of the ACA as an exercise in judicial activism performed after congressional Republicans failed to repeal the law.

“With the stakes this high, faithful adherence to principles that restrain the exercise of the judicial power is vital,” the House wrote. “That is not, however, how the district court approached this case,”

U.S. District Judge Reed O’Connor in December dismantled the ACA — a ruling that has been stayed pending appeal — after concluding that its individual mandate became unconstitutional when Congress scrapped its tax penalty. The decision endorsed a lawsuit launched by Republican state attorneys general, who are led by Texas Attorney General Ken Paxton and recently won the full support of the Trump administration.

“The district court’s order invalidating the entire Affordable Care Act extends judicial power … beyond its constitutional limits,” the Democratic attorneys general wrote Wednesday, echoing language from the GOP attorneys general of Montana and Ohio, who last month broke ranks to defend the health care law.

Wednesday’s court filings marked the completion of briefings by the main parties in the case. Oral arguments have been tentatively set for the second week of July.

After failing to repeal the ACA, congressional Republicans in 2017 eliminated the mandate’s tax penalty, which applied to Americans who had access to affordable health insurance but declined to obtain it. In doing so, many Republicans stressed that axing the penalty would not otherwise affect the law, Democrats have noted.

The House on Wednesday strongly advised the appeals court not to uphold Judge O’Connor’s decision. Doing so would “affirm a massive judicial overreach” and “deny vitally important care to millions,” it said.

The Democratic attorneys general accused their GOP counterparts of an end-run around legislative channels that preserved the ACA, which created widespread consumer protections and has helped roughly 20 million Americans obtain low- or no-cost health insurance.

“They ask this court to do what Congress — after years of debate and deliberation — repeatedly refused to do: dismantle the entire Affordable Care Act,” the Democratic attorneys general, led by California Attorney General Xavier Becerra, wrote Wednesday.

The U.S. Supreme Court will very likely take up the case if the Fifth Circuit affirms Judge O’Connor’s ruling. If it reverses the ruling, the high court’s involvement is less certain.

It’s not yet publicly known which judges will sit on the panel for the Fifth Circuit, which is one of the nation’s most conservative appeals courts. The Democratic lawmakers and attorneys general may hope that allegations of judicial overreach resonate with right-leaning judges who often espouse judicial restraint.

But it’s also true that Judge O’Connor depicted his ruling as respectful of congressional prerogatives. After deeming the individual mandate unconstitutional, he concluded that it was “plainly beyond the judicial power” to keep the remaining ACA intact, given that Congress saw the mandate as crucial when the ACA became law in 2010.

Democrats have argued that Congress’ feelings about the mandate’s importance in 2010 are no longer relevant, reasoning that Congress in 2017 clearly believed that the ACA should operate without the mandate.

Representatives of the U.S. Department of Justice and the Texas attorney general could not immediately be reached for comment on Wednesday.

The plaintiffs states are represented by their respective attorneys general.

The federal government is represented by the U.S. Department of Justice.

The defendant states are represented by their respective attorneys general.

The House is represented by Munger Tolles & Olson LLP, the Constitutional Accountability Center, and the Office of General Counsel for the U.S. House of Representatives.

The case is Texas et al. v. U.S. et al., case number 19-10011, in the U.S. Court of Appeals for the Fifth Circuit.