A federal appeals court on Monday blocked the law firm Gibson, Dunn & Crutcher from filing a pro-Obamacare amicus brief because the submission would have caused the disqualification of an unidentified judge.

The U.S. Court of Appeals for the Fifth Circuit's order pointed to a newly amended federal rule for appellate litigation and to a local court rule, both of which address circumstances where a court can reject an amicus brief if allowing it would force a judge to recuse.

The appeals court did not identify the judge, and the Fifth Circuit's clerk, Lyle Cayce, declined to comment on Monday's order. Former Gibson Dunn partner James Ho was confirmed in 2017 to a seat on the Fifth Circuit. It's not uncommon for judges to weigh potential conflicts of interest arising from the appearance in court of his or her previous law firm. Ho's wife, Allyson Ho, is a Gibson Dunn partner in Dallas. She joined the firm last year from Morgan, Lewis & Bockius.

James Ho, who'd been a Gibson Dunn appellate partner continually since 2010, said in a U.S. Senate questionnaire at the time of his confirmation: “For a period of time, I anticipate recusing in all cases where my current firm, Gibson, Dunn & Crutcher, represents a party.” He also said he would recuse in any case where his wife represents a side and that he would “evaluate any other real or potential conflict, or relationship, that could give rise to appearance of conflict.”

The Gibson Dunn team—litigation partner Stuart Delery and Washington associates Andrew Wilhelm and D. William Lawrence—represented two parties: First Focus and The Children's Partnership. Both groups are backing California and other states that are defending the Affordable Care Act.

Delery, formerly an Obama-era acting associate attorney general at Main Justice in Washington, was not immediately reached for comment Monday.

An amendment to the federal rules of appellate procedure that took effect in December 2018 said “a court of appeals may prohibit the filing of or may strike an amicus brief that would result in a judge's disqualification.”

Several appellate courts had adopted local rules forbidding the filing of an amicus brief that could cause the recusal of one or more judge, and the new federal rule harmonized how courts were handling amicus briefs and recusals. There was some opposition to the proposed rule, including the argument that amicus-based recusals are rare and the fact that the rule could “prove wasteful if an amicus curiae pays an attorney to write a brief which the court then strikes.”

Gibson Dunn's brief said the various parties in the case had consented to its filing. “No party, counsel for a party, or any person other than amici curiae and their counsel made a monetary contribution to the preparation or submission of this brief,” the Gibson Dunn lawyers wrote in a footnote.

The Fifth Circuit's order did not scrub Gibson Dunn's court filing entirely from the court's website, but it did lock the file and prevent anyone from opening it. The filing was, until now, publicly available on the Fifth Circuit's website.

“The ACA indisputably benefits millions of children, young adults, and their families,” the Gibson Dunn lawyers wrote in the amicus brief. “Infants born with complex medical issues can receive care without fear of annual or lifetime limits; young adults navigating their first jobs or higher education have the protection of their parents' insurance; other children receive care through Community Health Centers and home visits.”

The Gibson Dunn lawyers added: “Given that Congress did not repeal these provisions or countless others, there is no basis to conclude that it would want the courts to strike them down—particularly given the millions of American children whose lives have been changed (and saved) because of the ACA, and given how deeply the ACA is now woven into the fabric of the nation's healthcare system and economy.”

The Fifth Circuit hasn't yet set the argument date in case. The court also has not announced the names of the three-judge panel that will hear the case.

The Justice Department, which recently dropped its defense of Obamacare and is now backing Republican state challengers to the law, on Monday asked the appeals court to hear the case in July. “Prompt resolution of this case will help reduce uncertainty in the healthcare sector, and other areas affected by the Affordable Care Act,” Martin Totaro wrote in Monday's filing.

Here's the proposed Gibson Dunn amicus brief that the court struck: