After U.S. Supreme Court Ruling, It’s Back to States’ Laboratories for Religious Charter Schools

Last week, the U.S. Supreme Court divided 4–4 over whether denying a charter school application from a religious school would violate the Constitution’s prohibition on establishing or favoring a religion. The decision upheld the Oklahoma Supreme Court’s holding that chartering a school that would “evangelize” a particular faith violated state legislation and the Oklahoma and federal constitutions. As is the Court’s long-standing custom when it is equally divided, it did so without an opinion of its own. Justice Amy Coney Barrett did not participate.

As in most other states, a statute in Oklahoma gives a state board authority to “charter” schools. A charter designates the receiving school a “public school,” entitles it to receive public funds, and subjects it to various regulatory requirements — including that it be nonsectarian. In 2023, however, the Oklahoma Charter School Board was presented with an application by the Saint Isidore of Seville Virtual Charter School which proposed a curriculum and program that were vigorously and pervasively Catholic. The board awarded the charter anyway.

In June 2024, the Oklahoma Supreme Court set the board’s decision aside, holding that chartering the school simultaneously violated the Oklahoma charter school statute, the Oklahoma Constitution, and the federal Establishment Clause. Then, in January 2025 — notwithstanding my prediction to the contrary — the U.S. Supreme Court granted certiorari to review whether the denial of a charter to a school due to its religious character would violate the Establishment Clause. 

Last week’s affirmance of the state high court by an equally divided court formally lacks precedential force. Nevertheless, it tells us that as many justices were prepared to hold that Oklahoma was obligated to charter Saint Isidore’s as were prepared to hold the contrary. The Court’s affirmance thus announces, pragmatically speaking, a permissive policy: States may, but need not, exclude religious schools from their charter programs. This opens the door somewhat wider than it had been for states other than Oklahoma to move forward with religious chartering.

This widening does not suggest, however, that we should expect states to stampede through this newly ajar doorway. Indeed, legislatures often prove reluctant to open their public school systems to religion as fully as the law allows. Notably, after the Court’s 2002 decision in Zelman v. Simmons-Harris permitting but not requiring voucher programs to include religious schools, neither red nor blue legislatures took rapid advantage of their new flexibility, presumably concerned about tinkering with a public school system that most constituents accepted as it was.

In this moment, however, the decision whether to press on religious inclusion in charter programs is not the legislatures’ alone. The permissive effect of the Court’s decision makes it possible for market participants, with or without the cooperation of state charter school boards, to target their exclusion from charter laws. Any religious entrepreneur can file a charter application; a rejected applicant can litigate its rejection, and its opponents (as happened in Oklahoma) can litigate its acceptance. Given last week’s evenly divided Supreme Court, the state courts where many of these lawsuits will land may understand that the issue is largely up to them.

Will religious entrepreneurs — the next generation of schools like Saint Isidore’s — flock to set up such lawsuits? It is not clear. For one thing, the accelerating growth of vouchers — with the support of the Trump administration — means that there are ever more ways to secure public funding without being a charter school. And the U.S. Supreme Court has already said voucher programs cannot require nonsectarianism. Being a voucher recipient offers religious schools lower regulatory burdens than those imposed upon charters, including, notably, curricular flexibility and the opportunity to accept paying customers. Religious schools may also see political advantage in not antagonizing charter school boards and departments of education that may feel an obligation to enforce their charter statutes as written until and unless courts instruct them otherwise.

Writ large, proponents of educational choice may also see reasons to tread lightly on religious chartering. In particular, they may worry that some states would rather abolish charters altogether than accommodate sectarian schools in their programs — an option the Supreme Court has explicitly preserved. Religious charterers could lose both allies and ideological traction if they frustrate educational choice along nonreligious dimensions, especially without need to do so.

One final question is whether the Supreme Court has merely delayed resolution of this issue, owing to an idiosyncratic recusal. To answer this, one must know both why Barrett recused herself from the Oklahoma case and how she would have ruled had she not recused. Well-placed observers plausibly suppose that Barrett’s recusal was particular to the Oklahoma situation and that Barrett would likely be on the side of the religious charters were she to hear such a case. Barrett’s recusal itself suggests that she may have been surprised (as I was) that at least one of her conservative colleagues voted to uphold the Oklahoma Supreme Court. As to such speculations, of course, one never knows. But their plausibility might motivate any number of parties to try to push a new case in the Court’s direction.

If such a case ultimately arrives at the Supreme Court — or if it is litigated to completion in the state courts or the federal courts of appeal — it is hard to imagine that the core arguments will change much. Justice Clarence Thomas opened the oral arguments at the U.S. Supreme Court with the fundamental question: Is Saint Isidore’s a public school, because it asked to be a charter school, and the legislature defines charters as “public”? Or is it a private school, regardless how the legislature describes it, participating in a public program involving both public support and public regulation? If it’s the former, then states can, and perhaps even must, exclude religious charters; if it’s the latter, it must permit them. 

I argued in these pages a year ago that the latter argument is the better one; but fewer justices than I would have thought agreed. Whether Barrett will ultimately weigh in, whether other courts resolve this question state-by-state, or whether the issue recedes from the litigation agenda remains unknown. Regardless, I think, the larger trend is unmistakable: Every year, more and more students in religious schools will be supported by public funds.

Aaron Saiger is a professor at Fordham University School of Law and the director of Fordham Law School’s Urban Law Center.

Suggested Citation: Aaron Saiger, After U.S. Supreme Court Ruling, It’s Back to States’ Laboratories for Religious Charter Schools, Sᴛᴀᴛᴇ Cᴏᴜʀᴛ Rᴇᴘᴏʀᴛ (May 29, 2025), https://statecourtreport.org/our-work/analysis-opinion/after-us-supreme-court-ruling-its-back-states-laboratories-religious