The Fifth Circuit raised the question Wednesday of whether the Democrat-controlled U.S. House of Representatives and blue states can continue to defend the Affordable Care Act in the appeal of a district court’s invalidation of the landmark law.

The Fifth Circuit ordered parties to file supplemental briefs discussing whether the House and a coalition of Democratic attorneys general have standing to intervene in the Republican-led states’ lawsuit challenging the Obama administration’s signature legislative achievement. The request comes about two weeks before oral arguments are set to begin over whether a Texas federal judge properly concluded that the ACA must fall because its individual mandate became unconstitutional when Congress scrapped its tax penalty.

Because the Trump administration reversed course from its initial appeal of the decision, telling the Fifth Circuit in May that it agrees the whole law should be scrapped rather than just its coverage of people with preexisting conditions, the court’s request Wednesday asked: “What the appropriate conclusion is if the federal defendants’ change in position has mooted the controversy and no other defendant has standing to appeal.”

The states defending the ACA, including California and New York, along with the House, doubled down on the district court’s invalidation of the ACA as an egregious misuse of judicial power, urging the Fifth Circuit in May not to affirm a ruling that was “beyond its constitutional limits.”

Wednesday’s order throws into question who, if anyone, can appeal the controversial decision.

“What’s at stake is whether anyone can appeal the district court order holding that the entire ACA should be struck down,” Jonathan H. Adler, a law professor at Case Western Reserve University School of Law, said in an email. “Because the federal government no longer disputes any aspects of the court’s decision, there is a question as to whether the case should be considered moot and, if so, whether the lower-court decision should be vacated, or left to stand in place.”

The motives of the order coming from one of the nation’s most conservative appeals courts also raised some doubts about whether the Democratic lawmakers and attorneys general will be able to continue their fight.

“This is an ominous sign,” University of Michigan law professor Nicholas Bagley wrote on Twitter in response to Wednesday’s order. “If neither the blue states nor the House has standing, it would mean that no one has standing to appeal the decision. That would effectively leave the lower-court decision unappealable.”

“More generally, this order suggests that the Fifth Circuit panel may be hostile to the ACA and inclined to support the red states,” Bagley added. “The odds that the Fifth Circuit does something nasty to the health-reform law have gone up.”

Sarah Lovenheim, a spokesperson for California Attorney General Xavier Becerra, wrote in an email that their office is reviewing the supplemental briefing request.

`Republican-led states, including Texas and Arizona, sued the federal government over the ACA in 2018, arguing that the law’s individual mandate — upheld by the U.S. Supreme Court as a valid exercise of Congress’ taxation power — became unconstitutional when congressional Republicans repealed the accompanying tax penalty.

Since the individual mandate was unconstitutional, they argued, the rest of the law should be struck down as well because of how closely it was linked to the mandate.

The district court agreed in December in a ruling that shocked many, saying “Congress was explicit” about the individual mandate, which the court ruled unconstitutional, being so “essential” to the ACA that the mandate’s demise spelled the end for the whole law.

The government promptly asked the Fifth Circuit to intervene, but in late March, it filed a brief dropping its opposition to the ruling.

Attorneys general of New York, Texas and Arizona were not immediately available for comment Wednesday. The U.S. Department of Justice declined to comment.

The plaintiff states are represented by their attorneys general.

The defendant states are represented by their 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 U.S. is represented by the U.S. Department of Justice.

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.