“A neutral benefit program in which public funds flow to religious organizations through the independent choices of private benefit recipients does not offend the Establishment Clause,” Roberts wrote. “A State’s antiestablishment interest does not justify enactments that exclude some members of the community from an otherwise generally available public benefit because of their religious exercise.”

Under the Maine “tuitioning” program the court struck down on Tuesday, local governments lacking the population to run schools at a certain grade level typically pay for students to be educated at public or private schools of their choice. But, to avoid government funds being used for religious purposes, since 1981 the program has refused to pay for schools providing religious education.

In a 2020 decision on an educational aid program out of Montana, the Supreme Court ruled 5-4 that states could not exclude families or schools from student aid programs simply because the schools were backed by religious institutions.

However, that decision left open the question of whether states could block the use of their funds for explicitly religious or “sectarian” classes.

But in the case decided Tuesday, Roberts explicitly rejected Maine’ arguments that it was only targeting religious teaching and not whether a school was run by a religious group.

“Any attempt to give effect to such a distinction by scrutinizing whether and how a religious school pursues its educational mission would also raise serious concerns about state entanglement with religion and denominational favoritism,” the chief justice wrote.

In what is one of his final dissenting opinions before his planned retirement, Justice Stephen Breyer said the court seems to have lost all interest in enforcing the Constitution’s prohibition on establishment of religion.

“The First Amendment begins by forbidding the government from ‘mak[ing] [any] law respecting an establishment of religion.’ It next forbids them to make any law ‘prohibiting the free exercise thereof.’ The Court today pays almost no attention to the words in the first Clause while giving almost exclusive attention to the words in the second,” Breyer wrote.

Breyer also said the court was opening a Pandora’s box with its decision, suggesting that it was simply a way station to requiring all communities to use taxpayer funds to pay for religious schooling.

“We have never previously held what the Court holds today, namely, that a State must (not may) use state funds to pay for religious education as part of a tuition program designed to ensure the provision of free statewide public school education,” Breyer wrote.

“What happens once ‘may’ becomes ‘must’? Does that transformation mean that a school district that pays for public schools must pay equivalent funds to parents who wish to send their children to religious schools?” Breyer asked. “Does it mean that school districts that give vouchers for use at charter schools must pay equivalent funds to parents who wish to give their children a religious education?”

Justice Sonia Sotomayor also dissented, lamenting what she sees as a series of decisions bringing the government closer to direct sponsorship of religious activity.

“This Court continues to dismantle the wall of separation between church and state that the Framers fought to build,” Sotomayor warned. “It is irrational for this Court to hold that the Free Exercise Clause bars Maine from giving money to parents to fund the only type of education the State may provide consistent with the Establishment Clause: a religiously neutral one. Nothing in the Constitution requires today’s result.”

The court’s majority argued the dissenting justices were “wrong” to say Tuesday’s decision requires Maine to fund religious education, repeating a passage from the 2020 Montana decision: “As we held in Espinoza, a ‘State need not subsidize private education. But once a State decides to do so, it cannot disqualify some private schools solely because they are religious.’”

School choice advocates and religious groups nevertheless hailed the ruling as a significant step in a series of recent court decisions that have favored private education institutions.

“Today’s decision makes clear, once and for all, that the government may not bar parents from selecting religious schools within educational choice programs, whether because of their religious affiliation or the religious instruction they provide,” said Michael Bindas, an attorney for the Institute for Justice, a civil liberties law firm that brought the case to the high court alongside the conservative First Liberty Institute.

“Parents have a constitutional right to choose such schools for their children, and the court today held that a state cannot deny them that choice in programs that allow for other private options,” Bindas said in a statement.

Leaders of the National Education Association and American Federation of Teachers — top labor unions that sought to defend the Maine law in court — cast the ruling as an extreme decision that would promote radical education policy and undermine public schools.

“Forcing American taxpayers to fund private religious education — even when those private schools fail to meet education standards, intentionally discriminate against students, or use public funds to promote religious training, worship, and instruction — erodes the foundation of our democracy and harms students,” NEA President Becky Pringle said in a statement.

A national campaign sponsored by the Education Law Center and Southern Poverty Law Center meanwhile promised to pressure Maine’s legislature into repealing the state tuition program.

Still, the decision’s short-term reach appears to be limited — even if it creates new legal quandaries over the long term.

“Has anything enormous changed? No,” Derek Black, an education and civil rights professor at the University of South Carolina School of Law, said of Tuesday’s decision. “But what we are seeing is that all gray and ambiguous or open questions are being resolved to the benefit of religion.”

In the immediate aftermath, Black said the ruling poses serious challenges for states such as Maine and Vermont that have instituted private school voucher programs that prohibit funds from going to religious schools.

“It’s only affecting the states who say ‘We’re going to have a private program, but we want to keep public values in those private programs,’” Black said. More sweeping consequences could also lie in store.

Litigation is likely in the offing for governments that require religious schools to adhere to non-discriminatory admissions policies as part of school choice programs that use public funds. Advocates clamoring to fund religious-based charter schools with public money could harness the decision to raise money and attention for new court fights. And state governments could enact what Black described as “defensive policymaking” to avoid lawsuits.

“Not a single one of them wants to find themselves in federal district court, much less the Supreme Court,” Black said. “What decisions like this do is encourage states to create even more space and room for religion than the opinion itself did. What states do to avoid finding themselves in litigation could potentially be much broader.”

Juan Perez Jr. contributed to this report.