During an oral argument on Wednesday, the Supreme Court appeared all but certain to divide along party lines in a case that seeks to fundamentally expand the role religion plays in American public schools.

This isn’t surprising: Almost immediately after Republicans gained a supermajority on the Supreme Court, they started rewriting the Court’s religion decisions to make them more favorable to the religious right. One month after Justice Amy Coney Barrett’s confirmation gave the GOP their sixth vote on the Court, Roman Catholic Diocese v. Cuomo (2020) revolutionized the Court’s approach to religious objectors who seek exemptions from obeying the law — overruling a decision that was only a few months old in the process.

Since then, the Court has handed down case after case overruling previous religion decisions, usually to the benefit of the Christian right. The Court’s new decisions give religious conservatives far more ability both to ignore laws they do not like, and to demand that the government fund their religious institutions. After less than five years in power, the Court’s new majority has rendered the country’s religion jurisprudence unrecognizable, even to a lawyer who would have been considered an expert in the Constitution’s approach to religion less than a decade ago.

On the surface, Wednesday’s argument in Oklahoma Statewide Charter School Board v. Drummond merely signaled that the Court’s Republican majority will very likely take the next incremental step in its seemingly inexorable march toward integration of church and state.

Upon closer inspection, however, the Oklahoma argument was unlike some of this Court’s early forays into religion because some of the Republicans explicitly acknowledged that they are rewriting the Constitution’s approach to religion, and a few of them even appeared to signal where they want this revolution to end.

As Justice Brett Kavanaugh said late in the Oklahoma argument, the Court now has a “different constitutional understanding” of whether separation of church and state is even permitted. That new understanding, Kavanaugh suggested, is this: So long as an American can choose not to participate in a state-backed religious operation, church and state do not need to be separate — indeed, separation of church and state is often unconstitutional under this framework.

In Oklahoma, which is about whether states must pay for religious charter schools using taxpayers’ money, Kavanaugh’s new regime would mandate a great deal of state funding for religious schools, so long as parents retain a “choice” about where to send their child. Under Kavanaugh’s approach, if “no student is compelled to go to a religious charter school,” state charter school programs like the Oklahoma program at issue in this case must fund religious instruction.

Again, this approach to religion is fundamentally different from how previous generations of justices viewed the Constitution — in Everson v. Board of Education (1947), for example, the Court said that “no tax in any amount, large or small, can be levied to support any religious activities or institutions, whatever they may be called, or whatever form they may adopt to teach or practice religion.” But, at the very least, the Court’s new majority now appears to have settled on the rule it will apply in future cases seeking to mandate government funding of religious faith.

What is the Oklahoma case about?

Oklahoma is the culmination of a series of decisions that not only reject Everson, but also seek to turn it on its head. The rule is no longer that church and state must be separated. The Court’s current majority mandates that they must be entangled with each other.

In fairness, the right of citizens to choose whether to participate in religious institutions has animated the Court’s religion cases for quite a while. In Zelman v. Simmons-Harris (2002), a 5-4 Court ruled that states may voluntarily include religious schools in a private school voucher program, so long as parents ultimately got to decide whether to send their child to a religious school. But Zelman merely established that government funding of religious private schools is permissible, not that it is required.

That changed in a trio of cases that culminated in Carson v. Makin (2022). Carson held that, once a state sets up a private school voucher program, “it cannot disqualify some private schools solely because they are religious.” So, once a voucher program exists, state funding of religion is now mandatory.

That said, Carson also held that states are still allowed to “provide a strictly secular education in its public schools.” The question in Oklahoma is whether state charter school programs — charter schools are classified as nonreligious public schools under both federal law and the laws of 46 different states, even though they are often run in partnership with a private entity — are allowed to provide the strictly secular education the Court spoke of in Carson.

After Wednesday’s oral argument, there appeared to be broad willingness among the Court’s Republicans (minus Barrett, who is recused from this case) to expand religious schools’ access to public money once again. Those justices seemed ready to rule that Oklahoma’s public charter schools are actually private schools, and therefore, the state must fund religious charter schools. The specific school at issue in Oklahoma, St. Isidore of Seville Catholic Virtual School, would be the first religious charter school in the nation.

If you accept Carson as legitimate, it’s not that much of a stretch to conclude that religious charter schools are mandatory.

The state’s best argument that Carson does not apply to charter schools is that the Court held, in Biden v. Nebraska (2023), that an entity which “was created by the State to further a public purpose, is governed by state officials and state appointees, reports to the State, and may be dissolved by the State” is a public institution, unlike the private schools at issue in Carson. Oklahoma law provides that charter schools cannot exist without state sponsorship, and the state exerts considerable control over charter schools — including approving their curriculum and requiring them to be audited by the state.

But none of the five Republican justices who heard the Oklahoma case appeared persuaded that charter schools count as public entities that are allowed to be strictly secular. Chief Justice John Roberts, the closest thing this Court has to a moderate Republican, compared Oklahoma’s charter schools to government contractors — he pointed to the Court’s decision in Fulton v. City of Philadelphia (2021) a government contracting case which held that a city could not exclude religious adoption agencies that refuse to place children with same-sex couples from its broader adoption program.

Meanwhile, many of the justices appeared genuinely angry that religious schools have been excluded from state and federal charter school programs for as long as those programs have existed. Justice Samuel Alito went on a rant about how current law permits charter schools that teach that being LGBTQ is a “perfectly legitimate lifestyle,” but doesn’t permit the government to fund religious viewpoints. Kavanaugh, at one point, suggested that the longstanding rule establishing that charter schools must be secular is “rank discrimination against religion.”

In fairness, Kavanaugh at least acknowledged that his Court recently changed the rules. When Gregory Garre, the lawyer defending Oklahoma’s ability to have a nonsectarian charter school program, pointed out that both federal law and every relevant state’s law provides for secular charter schools, Kavanaugh responded that “at that point it was considered constitutional to discriminate against religious entities.”

Based on Wednesday’s argument, it appears likely that the Court will adopt the rule Kavanuagh articulated shortly thereafter — that government funding of religious schools is required so long as individual citizens retain the choice to send their children to a non-religious school.

Will there be any limits on the Court’s new rule?

Democratic Justice Elena Kagan, for her part, spent much of the argument trying to draw out the implications of her Court’s new approach to religion. What if a religious charter school refused to educate children who do not share the school’s faith? Or suppose that a religious charter school wanted to toss out state curricular standards altogether? She brought up the example of an Orthodox Jewish yeshiva where instruction would focus almost entirely on the Talmud, to the exclusion of topics like math and English. Would taxpayers be required to fund this school as well?

Indeed, the implications of the Court’s new rules could be quite significant if they are applied outside of the public school context. If a religious individual believes it is a sin to ride a bus with people of another faith, does that mean that the state must now provide faith-segregated buses? If a city council puts out cookies and potato chips for attendees to snack on, do they violate the Constitution if these snacks are not kosher or halal? What if they are both kosher and halal, but they cannot be eaten by someone who holds the idiosyncratic religious belief that it is a sin to eat unhealthy food? Is the government required by the Constitution to give this person carrot sticks?

Kavanaugh’s view, at the very least, suggests that it is unconstitutional discrimination for the government to provide a benefit of any kind without also providing religious versions of that same benefit.

It’s worth noting that Oklahoma is the second oral argument in the last several days where the Republican justices appeared eager to reshape public schools in a Christian conservative image. Last week, in Mahmoud v. Taylor, most of the justices sounded extremely sympathetic to religious parents who objected to books being taught in public schools that have LGBTQ characters. Depending on how the Court rules in Mahmoud, it could impose such high burdens on schools that want to teach such books that public school districts will have little choice but to exclude them — effectively imposing a “Don’t Say Gay” rule on every public school in the country.

The Court’s rulings in both cases will come in the next few months. But for now, it appears the Republican justices’ religious conservative revolution is likely to march onward, remaking public schools, and potentially many other public institutions.