In an opinion Thursday, Justice Ruth Bader Ginsburg, speaking for a unanimous U.S. Supreme Court, had unusually harsh criticism of a federal appellate panel for a practice that some court experts say the justices often embrace themselves.

Violation of the "party presentation" principle—central to Thursday's ruling—is not often the basis for deciding a high court case. The principle refers to the long-standing feature of the court system that the parties involved in litigation, and not judges, are responsible for raising the legal issues a court must resolve.

That principle rarely appears in a Supreme Court decision, and the ruling was all the more remarkable that its author—Ginsburg—rebuked a panel of the U.S. Court of Appeals for the Ninth Circuit in accusatory terms that said the court's "transformation" of a case went "well beyond the pale."

Ginsburg's opinion was in the case United States v. Sineneng-Smith. Evelyn Sineneng-Smith, who operated an immigration consulting firm in San Jose, California, was convicted of violating a federal law making it a felony to "encourage or induce an alien to come to, enter, or reside in the United States, knowing or in reckless disregard of the fact that such coming to, entry, or residence is or will be in violation of law."

Sineneng-Smith helped undocumented immigrants apply for labor certification even though she knew they did not meet the application-filing deadline. For her services, she collected more than $3.3 million from them between 2001 and 2008. In appealing her conviction, her attorney raised the same arguments presented to the district court, but then her appeal moved "onto a different track," according to Ginsburg.

"Instead of adjudicating the case presented by the parties, the appeals court named three amici and invited them to brief and argue issues framed by the panel, including a question Sineneng-Smith herself never raised earlier: 'Whether the statute of conviction is overbroad … under the First Amendment,'" Ginsburg wrote.

Lawyers for the parties to the appeal were assigned a secondary role, Ginsburg said. The three amici appointed to brief and argue were the circuit's Federal Defender Organizations (as a group), the Immigrant Defense Project, and the National Immigration Project of the National Lawyers Guild. The panel identified three issues for the briefing and gave amici 20 minutes to argue and 10 minutes to Sineneng-Smith's counsel.

"The party presentation principle is supple, not ironclad," Ginsburg wrote. "There are no doubt circumstances in which a modest initiating role for a court is appropriate. But this case scarcely fits that bill."

Although a court is not "hide-bound" by a party's counsel's precise arguments, Ginsburg said "the Ninth Circuit's radical transformation of this case goes well beyond the pale." The Ninth Circuit's judgment was vacated and the case remanded "for reconsideration shorn of the overbreadth inquiry interjected by the appellate panel and bearing a fair resemblance to the case shaped by the parties."

The court, in another unusual move, issued an addendum identifying cases from 2015 to 2020 in which the justices called for supplemental briefing or appointed an amicus curiae. Ginsburg, in a footnote, wrote: "None of them bear any resemblance to the redirection ordered by the Ninth Circuit panel in this case."

In the addendum, the court highlighted cases where it sought supplemental briefing to decide whether a controversy existed to support review in the first place; to determine whether a case could be resolved more narrowly than the question presented; and whether a constitutional issue was implicated by the question presented, among other reasons.

The Ninth Circuit panel that decided the case below included Judges A. Wallace Tashima, Marsha S. Berzon, and Andrew D. Hurwitz. Judge Stephen Reinhardt, a member of the panel who heard argument in the case, died while it was pending and was replaced by Hurwitz.

Some appellate lawyers were quick to note that the justices were criticizing the Ninth Circuit panel for "something the justices do all the time—focus on issues not raised in the parties' briefs," as law professor Steve Vladeck put it.

One recent example was the court's order for supplemental briefing on whether the political question doctrine or other justiciability doctrines apply to the pending cases on subpoenas of President Donald Trump's financial records.

David Ziff of the University of Washington Law School criticized the addendum to Thursday's opinion.

"The scope of the 'principle of party participation' is completely unclear," Ziff said on Twitter. "The court offers an addendum to explain how its own prior appointments of counsel to present un-advanced arguments are all different. But the addendum doesn't explain why those differences matter."

In a 2009 law review article on the party presentation principle, Amanda Frost of American University Washington College of Law said there are good reasons to promote "judicial issue creation" in certain types of cases.

Frost argued that "federal judges are assigned the task of settling the meaning of disputed questions of law, not just for the parties, but for all who must comply with it. Furthermore, they must do so free from outside influence. As a result, courts have the power to look beyond the parties' arguments when failing to do so would lead to an inaccurate or incomplete description of the law."

In the Supreme Court case, Deputy Solicitor General Eric Feigin represented the government. Mark Fleming, a partner at Wilmer Cutler Pickering Hale and Dorr, was counsel to Sineneng-Smith.