WASHINGTON — The Supreme Court’s conservative majority seemed to be searching on Monday for a narrow way to rule in favor of a former high school football coach who lost his job for praying at the 50-yard line after his team’s games.
The task was complicated by factual disputes over the conduct of the coach, Joseph A. Kennedy, and the varying rationales offered by the school district in Bremerton, Wash., for disciplining him.
The case pits the rights of government workers to free speech and the free exercise of their faith against the Constitution’s prohibition of government endorsement of religion and Supreme Court precedents that forbid pressuring students to participate in religious activities.
In his eight years as an assistant coach at Bremerton High School, Mr. Kennedy routinely offered prayers after games, with students often joining him. He also led and participated in prayers in the locker room, a practice neither he nor his lawyers now defends.
In 2015, after an opposing coach told the principal that he thought it was “pretty cool” that Mr. Kennedy was allowed to pray on the field, the school board instructed Mr. Kennedy not to pray if it interfered with his duties or involved students.
The two sides disagree about whether Mr. Kennedy complied.
A school official recommended against renewing the coach’s contract for the 2016 season, and Mr. Kennedy did not reapply for the position.
According to Paul D. Clement, one of Mr. Kennedy’s lawyers, all that was at issue in the case now was whether his client could offer a brief, silent and solitary prayer of thanks after his team’s games. Earlier episodes were not relevant, Mr. Clement said.
“Coach Kennedy was fired for that midfield prayer, not for any earlier practices,” Mr. Clement said, adding that the school district’s actions violated Mr. Kennedy’s First Amendment rights.
Richard B. Katskee, a lawyer for the Bremerton School District, said it was entitled to require that its employees refrain from public prayer if students were likely to feel coerced into participating.
“He insisted on audible prayers at the 50-yard line with students,” Mr. Katskee said of Mr. Kennedy. “He announced in the press that those prayers are how he helps these kids be better people.”
Mr. Katskee was challenged by some of the more conservative justices, who said the district had initially argued that it could stop Mr. Kennedy from praying on a different ground: that the school would be perceived to be endorsing religion by allowing it. They suggested that the fear of coercion was a rationalization after the fact.
“One of the difficulties of this case is getting one’s hands around the district’s rationale,” Justice Neil M. Gorsuch said.
Justices across the ideological spectrum peppered the lawyers with hypothetical questions. Chief Justice John G. Roberts Jr. asked whether Mr. Kennedy could have prayed aloud while standing with his arms outstretched. Justice Amy Coney Barrett went a little further: “Let’s say he says the ‘Our Father’ with arms outstretched and it starts causing a lot of havoc in the stands.”
Justice Samuel A. Alito Jr. asked whether Mr. Kennedy would have been disciplined for protesting the invasion of Ukraine, climate change or racial injustice. Justice Sonia Sotomayor wondered if a public high school could discipline “a coach who decides to put a Nazi swastika on their arm and go to the middle of the field and pray.”
Justice Brett M. Kavanaugh asked whether a school could “fire the coach for the sign of the cross right before the game.”
The lawyers responded by proposing lines the justices could draw. Mr. Clement said it mattered whether a coach’s speech had “an instructional component” and whether a religious exercise was fleeting.
Mr. Katskee said it mattered whether the coach was “making himself the center of attention at the center of the field.”
Justice Kavanaugh, himself a basketball coach, said the possibility of coercion posed an authentic problem.
“What about the player who thinks, ‘If I don’t participate in this, I won’t start next week?’” he asked, adding that “every player’s trying to get on the good side of the coach.”
Justice Kavanaugh said the solution was elusive. “I don’t know how to deal with that, frankly,” he said.
Mr. Clement said the school district had not relied on that argument. “This is not a case where the government took action because of coercion concerns,” he said. “The record is crystal-clear that they were concerned about endorsement.”
He added that Mr. Kennedy’s conduct did not amount to coercion in any event. “When the coach is by himself at the midfield giving a 15-second fleeting prayer,” he said, “if you call that coercion, you are making an important category mistake.”
Both Chief Justice Roberts and Justice Alito indicated that they wished the facts of the case were more straightforward.
“What if all that were off the table?” Chief Justice Roberts asked Mr. Katskee, referring to the tangled history of Mr. Kennedy’s dispute with the school district. “It’s simply the coach going out to midfield, kneeling — taking a knee — and that’s it?”
Justice Alito, too, presented a simplified version of the controversy. “Forget about all of the complicated facts in this case,” he told Mr. Katskee.
Mr. Katskee said the hypothetical questions presented a closer question than the one actually before the court.
The tenor of the questioning from the court’s conservative members was unsurprising, as four of them had issued a statement questioning a preliminary ruling in favor of the officials from the U.S. Court of Appeals for the Ninth Circuit, in San Francisco.
“The Ninth Circuit’s understanding of the free speech rights of public-school teachers is troubling and may justify review in the future,” Justice Alito wrote at the time. He was joined by Justices Gorsuch, Kavanaugh and Clarence Thomas.
“What is perhaps most troubling about the Ninth Circuit’s opinion,” Justice Alito added, “is language that can be understood to mean that a coach’s duty to serve as a good role model requires the coach to refrain from any manifestation of religious faith — even when the coach is plainly not on duty.”
After further proceedings, a unanimous three-judge panel of the Ninth Circuit again ruled against Mr. Kennedy, saying that school officials were entitled to forbid his public prayers to avoid a potential violation of the First Amendment’s prohibition of government establishment of religion.
The full Ninth Circuit declined to rehear the case over the objections of 11 judges. The two sides sharply disagreed about how to characterize Mr. Kennedy’s actions.
Judge Milan D. Smith Jr., the author of the panel opinion, wrote that “Kennedy made it his mission to intertwine religion with football.”
In response, Judge Diarmuid F. O’Scannlain said the panel opinion had things backward. “It is axiomatic that teachers do not ‘shed’ their First Amendment protections ‘at the schoolhouse gate,’” he wrote, quoting a 1969 Supreme Court decision. “Yet the opinion in this case obliterates such constitutional protections by announcing a new rule that any speech by a public-school teacher or coach, while on the clock and in earshot of others, is subject to plenary control by the government.”
On Monday, Justice Stephen G. Breyer said the case, Kennedy v. Bremerton School District, No. 21-418, presented unusual challenges. “This may be a case about facts and not really much about the law,” he said.