Nowhere in the Trinity Lutheran Church v. Comer opinion are the terms “school voucher,” “tuition tax credit,” or “education savings account” mentioned. But let there be no doubt that school voucher advocates and opponents alike view this case as a marker for whether the Supreme Court will require states to allow parents and children to use publicly funded school vouchers for religious schools. In Trinity Lutheran, the Court held that denial of an otherwise available public benefit to religious institutions violated the Trinity Lutheran Church’s First Amendment free exercise rights, even in the face of state constitutional prohibitions on the use of public funds for religious purposes. While I will leave the broader implications of the Trinity Lutheran decision to my colleagues (such as Profs. McConnell and Sonne) who are experts in religious liberties, and despite the fact that in a footnote the plurality of the Court purports to limit the decision to the narrow facts of the case, Trinity Lutheran should provide cause for concern among those who oppose school vouchers generally and those who oppose vouchers for religious schools specifically.

For nearly three decades, the expansion of public charter schools and establishment of publicly funded school voucher programs (and their close cousins, tuition tax credits and education savings accounts) have been among the chief policy objectives of market-based school reformers. Apart from the political and fiscal barriers to the establishment of voucher programs, the voucher movement has been hamstrung by federal and state constitutional litigation, particularly lawsuits aimed at those programs that would allow vouchers to be used at religious schools. While there are only about 25 publicly funded voucher programs in 14 states, the school voucher movement has nonetheless quietly grown and, more important, has been recently energized by the election of Donald Trump and the appointment of voucher proponent, Betsy DeVos, to Secretary of Education. With the political winds shifting, voucher opponents may need to make their case in court and Trinity Lutheran may make that case more difficult.

The first big contemporary test for school vouchers came in the 2002 Zelman v. Simmons-Harris case in which the Supreme Court upheld the Cleveland voucher program—in which 96.4 percent of voucher recipients used their vouchers at religious schools—in the face of an Establishment Clause challenge. There the Court upheld the Cleveland program because it did not endorse religion or provide direct government funding to religious schools. Rather, the Court held, the “program is entirely neutral with respect to religion. It provides benefits directly to a wide spectrum of individuals, defined only by financial need and residence in a particular school district. It permits such individuals to exercise genuine choice among options public and private, secular and religious. The program is therefore a program of true private choice.” It did not directly encourage or inhibit religion and therefore did not violate the First Amendment’s separation of church and state.

Zelman cleared the Establishment Clause underbrush for expansion of voucher programs by making it clear that states may allow families to use public school vouchers at religious schools. Yet the question remained whether states must open up an otherwise generally available aid program—like vouchers—to religious schools. In the wake of Zelman, the expansion of vouchers has been impeded in the state courts. Specifically, those programs that would, consistent with Zelman, permit use of vouchers at religious schools have been challenged under the so-called “Blaine Amendments” contained in about three quarters of the state constitutions. These religion clauses or “no aid” provisions—like that in the Missouri Constitution at issue in Trinity Lutheran—prohibit state support of religious institutions, including the use of tax dollars to support religious schools.

It is against that backdrop that the Trinity Lutheran Church sought to replace its pea-gravel playground surface by applying to the Scrap Tire Program sponsored and funded by the Missouri Department of Natural Resources. That program provided reimbursement funds on a competitive basis to qualifying nonprofit organizations that install playground surfaces made from recycled tires. Although Trinity Lutheran ranked 5th out of 44 organizational applicants on the relevant criteria, the church was not among the 14 organizations awarded grants because, according to the Department’s rejection letter, the state was prohibited from providing funds to religious institutions under the state constitution’s no-aid provision.

After being upheld in U.S. District Court and the Eight Circuit, the Department’s rejection of Trinity Lutheran’s funding application landed in the SCOTUS. There the Court held, 7-2, that the denial of the funding application violated the church’s free exercise rights and discriminated against the church by denying the Church an otherwise available public benefit on account of its religious status. “The express discrimination against religious exercise here is not the denial of a grant, but rather the refusal to allow the Church—solely because it is a church—to compete with secular organizations for a grant,” wrote Justice Roberts. Stated differently, once the state opens a benefit to the public, the Court held, it cannot deny that benefit to an institution based on its status as a religious institution.

In reaching its conclusion, the Court specifically distinguished its Locke v. Davey decision in which it upheld the denial of public scholarship funds to a student who wished to pursue a “devotional or theology” degree at a religious college. The Washington state scholarship program was generally available to high-achieving students who wanted to pursue postsecondary degrees. Davey, who wished to pursue a devotional degree, was denied the scholarship and sued, alleging that the denial violated his free exercise rights. The Court, noting that there is “room for play in the joints” between the establishment of religion and the free exercise of religion, upheld the state’s denial of the scholarship. “Davey was not denied a scholarship because of who he was; he was denied a scholarship because of what he proposed to do—use the funds to prepare for the ministry” and this ran afoul of the state’s Establishment Clause interests.

Unlike the facts in Locke, the plurality argued, the State of Missouri explicitly discriminated against the Trinity Lutheran Church because of its nature, not what it wanted to do with the public monies. In essence, Trinity Lutheran was forced to choose between being a church and receiving an otherwise available public benefit. That penalty on the free exercise of religion could not pass strict scrutiny, the Court concluded.

The decision was immediately lauded by the Trump Administration as a victory for school voucher proponents and derided by some civil rights organizations. “Religious freedom should protect unwilling taxpayers from funding church property, not force them to foot the bill,” wrote Daniel Mach, director of the ACLU’s Program on Freedom of Religion and Belief.

As sweeping as the ruling seems at first blush, in footnote three the Court took pains to note that “[t]his case involves express discrimination based on religious identity with respect to playground resurfacing. We do not address religious uses of funding or other forms of discrimination.” Indeed, despite objections from Justices Thomas and Gorsuch, the plurality highlighted the status-use distinction and, at least in voucher opponents’ eyes, seemed to suggest that the religion-neutral use of public funds to enhance public health and safety makes Trinity Lutheran a rare case.

Upon closer examination, however, footnote 3 and the status-use distinction may be a thin bulwark against the inevitable argument that Trinity Lutheran and the Free Exercise Clause require states to allow families to spend school vouchers at religious schools. After all, if vouchers may be used at private secular schools, but cannot be used at private religious schools, isn’t that the denial of an otherwise generally available public benefit just because of the schools’ status as religious schools? So long as the religious schools agree to use the vouchers for the non-religious aspects of their educational program (much like the resurfacing of a playground), the state’s Establishment Clause interests appear to have been met for such generally available benefits.

I’ve read footnote three over and over and I don’t see how it limits or narrows the Court’s holding. It merely seems to say that the Court is only dealing with the resurfacing of a playground on church property right now. They’ll decide whether it’s unlawful discrimination to deny the use of vouchers at religious schools at a later date. That later date will come, and the one-two punch of Zelman’s “may” and Trinity Lutheran’s “must” may open public school voucher programs to all private schools whether secular or nonsecular.

William Koski is the Eric and Nancy Wright Professor of Clinical Education and the founding director of the Youth and Education Law Project (YELP) at Stanford Law School.