The Supreme Court appeared open on Wednesday to allowing Oklahoma to use government money to run the nation’s first religious charter school, which would teach a curriculum infused by Catholic doctrine.
Excluding the school from the state’s charter-school system would amount to “rank discrimination against religion,” Justice Brett M. Kavanaugh said during the oral argument.
The main question in the case is whether the First Amendment permits — or even requires — states to sponsor and finance religious charter schools, which are public schools with substantial autonomy. A decision endorsing such schools would spur their spread, extend religion’s extraordinary winning streak at the Supreme Court and further lower the wall separating church and state.
The Oklahoma school, St. Isidore of Seville Catholic Virtual School, is to be operated by the Archdiocese of Oklahoma City and the Diocese of Tulsa, and it aims to incorporate Catholic teachings into every aspect of its activities.
After Oklahoma’s charter school board approved the proposal to open St. Isidore, the state’s attorney general, Gentner Drummond, sued to stop it. Mr. Drummond, a Republican, said a religious public school would violate the First Amendment’s prohibition of government establishment of religion and the State Constitution’s ban on spending public money to support religious institutions.
The justices appeared to be divided along the usual ideological lines, with the court’s Republican appointees largely sympathetic to the school and its Democratic ones quite wary. But Justice Amy Coney Barrett recused herself from the case, raising the possibility of a tie vote if a single Republican appointee joined the three Democratic ones. That would leave a state court decision rejecting the school intact.
Chief Justice John G. Roberts Jr., who asked questions supportive of both sides, seemed to be the most likely member of such a potential alliance.
In earlier cases from Maine and Montana, the court ruled that states that decide to create programs to help parents pay for private schools must allow them to choose religious ones. Those decisions, Chief Justice Roberts said, “involved fairly discrete state involvement” while Oklahoma’s supervision of the new school “does strike me as much more comprehensive involvement.”
Later in the argument, though, he suggested that another of the court’s decisions required allowing the school.
A ruling in favor of the school could affect laws in 46 other states that authorize charter schools, said Gregory G. Garre, a lawyer for Mr. Drummond. It would also, he added, blur a line established in earlier Supreme Court cases distinguishing between government money provided to parents to spend on private schools, including religious ones, and government support provided directly to religious schools.
The dispute is the third major case dealing with religion to be argued before the justices in the space of about a month. In March, the court seemed poised to rule that a Catholic charity in Wisconsin was entitled to a tax exemption that had been denied by a state court on the grounds that the charity’s activities were not primarily religious. Last week, the court signaled that it was most likely to rule that parents with religious objections may withdraw their children from classes in which storybooks with L.G.B.T.Q. themes are discussed.
Since 2012, when the court unanimously ruled that religious groups were often exempt from employment discrimination laws, the pro-religion side has won all but one of the 16 signed decisions in argued cases that concerned the First Amendment’s religion clauses.
Much of Wednesday’s argument centered on the factual question of whether St. Isidore had been created and would be controlled by the state, making it a public school.
Lawyers for St. Isidore and the state agency that had approved it said the school was privately created and would be independently operated.
But Justice Elena Kagan said that St. Isidore and charter schools like it have many hallmarks of “regular public schools.”
“They accept everybody,” she said. “They’re free. They can be closed down by the state. There’s a good deal of curricular involvement by the state, approvals by the state. They have to comply with all the state standards.”
Justice Neil M. Gorsuch suggested that St. Isidore was sufficiently independent of Oklahoma but said other states could exert more control, by, for instance, requiring public officials to serve on charter schools’ boards.
“Have you thought about that boomerang effect for charter schools?” he asked James A. Campbell, a lawyer for the Oklahoma agency that approved St. Isidore.
Mr. Campbell said states “can set up their charter school programs as they see fit” but added that “there are significant trade offs, because part of what makes charter schools great is the autonomy that they’re provided.”
Justice Gorsuch returned to the point later in the argument. “A holding here may apply in some states and may not apply in others,” he said.
D. John Sauer, in his first argument as U.S. solicitor general, argued in favor of St. Isidore on behalf of the Trump administration.
“Participation in charter schools is mediated through two layers of private choice, both of the applicants who create the schools and the parents who choose to send their children to them,” he said. “Oklahoma does not control their programs, staffing or curriculum.”
Mr. Garre said that a decision in favor of St. Isidore “would result in the astounding rule that states not only may but must fund and create public religious schools, an astounding reversal from this court’s time-honored precedents.”
Justice Kavanaugh took the opposite view. “All the religious school is saying is ‘don’t exclude us on account of our religion,’” he said, adding: “You can’t treat religious people and religious institutions and religious speech as second class in the United States.”
Justice Barrett recused herself from the case, Oklahoma Statewide Charter School Board v. Drummond, No. 24-394, but did not say why. She is a former law professor at Notre Dame, whose religious liberty clinic represents the charter school, and is close friends with Nicole Garnett, a professor there who has assisted St. Isidore.
The school said it would welcome students of “different faiths or no faith.” It was less categorical about teachers, saying that all Oklahoma charter schools are free to adopt their own personnel policies.
The state’s Supreme Court ruled against the school, with the majority saying it would “create a slippery slope” that could lead to “the destruction of Oklahomans’ freedom to practice religion without fear of governmental intervention.”
“St. Isidore is a public charter school,” the majority said, noting that the state law allowing such schools requires them to be nonsectarian. “Under both state and federal law,” the majority ruled, “the state is not authorized to establish or fund St. Isidore.”
In the most recent decision from the U.S. Supreme Court about government support for religious schools, Carson v. Makin in 2022, the majority ruled that Maine could not exclude religious schools from a state tuition program.
But Chief Justice Roberts, writing for the majority, said that “Maine may provide a strictly secular education in its public schools.”
In dissent, Justice Stephen G. Breyer, who retired that year, said that even Maine’s program, limited to private schools, was problematic.
“Members of minority religions, with too few adherents to establish schools, may see injustice in the fact that only those belonging to more popular religions can use state money for religious education,” Justice Breyer wrote. “Taxpayers may be upset at having to finance the propagation of religious beliefs that they do not share and with which they disagree.”
Justice Kagan echoed that point on Wednesday, saying the state’s position favored mainstream religions at the expense of “religions that seem peculiar to many eyes, but are deeply felt.”