Does the U.S. Constitution require states to subsidize religious private schools? For decades, the answer has been an unambiguous no; indeed, the Supreme Court has held that, to the contrary, the Constitution prohibits government subsidies for religious organizations. Last June, however, Chief Justice John Roberts turned that rule on its head with his opinion in Trinity Lutheran v. Comer, which for the first time held that the Constitution sometimes compels states to provide public funds directly to a house of worship. Roberts’ decision feigned modesty, but it also seemed to open the door to the possibility of mandatory government funding of religious education.

On Monday, the New Mexico Supreme Court grappled with the ramifications of Trinity Lutheran in Moses v. Ruszkowski. Moses boils down to largely the same question asked by Lutheran: Can a state deny government benefits to sectarian schools because of their religious character without violating the First Amendment? Under Trinity Lutheran, at least, it appears that they cannot. This compulsory entanglement of church and state illustrates just how dramatically Roberts has undermined the constitutional separation of church and state.

In many ways, Moses is a perfect sequel to Trinity Lutheran, because it should clarify the radical scope of Roberts’ ostensibly narrow opinion. Trinity Lutheran revolved around a Missouri church’s “Learning Center,” which is used “to teach the Gospel to children.” The center includes a playground, and in 2012, the church applied for a grant from the state to cover the cost of playground resurfacing. The grant program helped nonprofit entities buy rubber playground surfaces made from recycled tires. Missouri rejected the church’s application, citing a provision of the state constitution that forbids the use of public funds “in aid of any church, sect or denomination of religion.” Trinity Lutheran sued, alleging that Missouri had violated its rights under the First Amendment’s Free Exercise Clause. The Supreme Court ruled in its favor, holding that a state may not deny a “public benefit” to religious institutions “solely because of their religious character.”

This compulsory entanglement of church and state illustrates just how dramatically Roberts has undermined the constitutional separation of church and state.

As Justice Sonia Sotomayor explained in a dissent, this conclusion veers so far off course that it collides with a different constitutional provision: the Establishment Clause. The Supreme Court has long interpreted the Establishment Clause, which bars the government from “respecting an establishment of religion,” to proscribe the government from funding the exercise of religion. Roberts wriggled around this rule by insisting that the Missouri grant merely subsidized a playground, not religion itself, and thus funded strictly secular activities. But Sotomayor deftly dispensed with this fiction. “The Church has a religious mission, one that it pursues through the Learning Center,” she wrote. “The playground surface cannot be confined to secular use any more than lumber used to frame the Church’s walls, glass stained and used to form its windows, or nails used to build its altar.”

At the end of her dissent, Sotomayor warned that Roberts’ decision would quickly spread to cases that dealt with more than just playgrounds. She was quite right. The very next day, the court vacated two lower court decisions: one ruling from the Colorado Supreme Court holding that the state constitution barred a school district from funding vouchers for religious schools, and another from the New Mexico Supreme Court holding that the state constitution barred the legislature from funding (secular) textbooks for religious schools. SCOTUS directed both courts to reconsider these rulings “in light of” Trinity Lutheran.

The reconsideration did not get far in Colorado: In January, the case was abruptly dismissed after residents voted out the pro-voucher members and replaced them with new members eager to end the litigation. But the New Mexico case has dragged on, and on Monday, the state Supreme Court heard arguments, again, in Moses v. Ruszkowski. In 2015, the court unanimously found that the New Mexico Constitution strictly prohibited the legislature from aiding sectarian schools. Now, though, the justices had been ordered to decide if this prohibition violates the First Amendment’s Free Exercise Clause. They had to decide, in short, if Roberts’ opinion was really as sweeping as Sotomayor had charged.

With perceptive exasperation, a majority of the court seemed resigned to the fact that, yes, Roberts’ opinions tied their hands, casting serious doubt on the state constitutional provision that bars aid to religious schools. Their state’s clause is expansive and unambiguous: It declares that no funds “appropriated, levied or collected for educational purposes, shall be used for the support of any sectarian, denominational or private school, college or university.” In its previous decision, the court had predictably read the provision to prevent the legislature from paying for sectarian schools’ textbooks with public funds. While the textbooks themselves were secular, the court explained, they still helped parochial schools further their religious mission, allowing them to divert money they would have spent on “instructional materials … to other uses in their schools.” But the justices were worried this holding now clashed with Trinity Lutheran, as SCOTUS hinted in June.

“How do we get around Trinity?” Justice Petra Jimenez Maes asked Frank Susman, who argued that religious schools may not get free textbooks under the state constitution. “We have to apply that principle,” Maes asserted. “I’m having trouble saying Trinity does not apply to this section.”

But Justice Edward Chávez seemed to see a way to navigate around Roberts’ Trinity point in Moses. “The classification being created,” he pointed out, is not religious vs. secular, as it was in Trinity. It’s schools “who are under exclusive control of the state”—i.e., public schools—“and those who are under the control of someone else”—i.e., private schools.

With perceptive exasperation, a majority of the court seemed resigned to the fact that, yes, Roberts’ opinions tied their hands.

Chávez is exactly right: Unlike Missouri’s state constitution, the New Mexico Constitution doesn’t bar aid to religious educational institutions; it bars aid to private ones, including religious schools. Theoretically, that distinction could get Moses v. Ruszkowski out from under Trinity Lutheran. But Justice Charles W. Daniels quickly jumped in to undercut that hope.

“Let’s talk about the elephant in the room,” the justice told Susman. “The reason that provision was put in our state constitution was because [Congress said] we wouldn’t be allowed to be a state … unless we incorporated a constitutional provision prohibiting aid to religious and sectarian schools. And so in order to become a state we did that, but we added private schools.” Daniels concluded by stating that the “real motivation” of the provision was Congress’ anti-Catholic animus.

Daniels was partly correct. When New Mexico became a state in 1912, Congress demanded that it adopt some kind of “Blaine Amendment”—a constitutional provision forbidding government aid to parochial schools. Some historians argue that Blaine Amendments were motivated solely by anti-Catholic sentiment, although this claim is strongly contested and, at a minimum, dramatically oversimplified. Moreover, there’s no actual evidence that New Mexico enacted its absolute ban on taxpayer funding for religious education with any discriminatory intent. It may just as likely have been motivated by a desire, shared by many state constitutional drafters, to funnel all educational funding to the young state’s nascent public education system.

Nonetheless, Eric Baxter, an attorney for the conservative Becket Fund for Religious Liberty, arguing for the parochial schools, told the justices that the New Mexico Constitution was indisputably motivated by anti-Catholic sentiment. To see why, Baxter said, the justices had to look beyond the plain text of the constitution to its history and context in order to glean discriminatory animus on the basis of religion. In making this ask, Baxter implored the court to do precisely what opponents of Donald Trump’s travel ban want the U.S. Supreme Court to do to reveal Trump’s anti-Muslim animus as the motivation behind the ban. Yet Becket has conspicuously declined to take sides with the Muslim families suing against the travel ban, while jumping at the opportunity to defend New Mexico’s mostly Christian religious schools.

Toward the end of arguments, Susman noted that California, Oregon, Nebraska, Massachusetts, Missouri, South Dakota, and Hawaii all have bans on public aid to religious schools like New Mexico’s—bans each state’s Supreme Court has upheld.

“Those,” Daniels cautioned, “were all before Trinity Lutheran.” Now “some of those citations are suspect, don’t you think?”

The answer, unfortunately, may well be yes. Although the justices seemed divided—and clearly concerned about the Establishment Clause implications of the case—they all sounded eager not to get reversed by the U.S. Supreme Court. To play it safe, a majority of the justices sounded prepared to interpret Trinity Lutheran broadly. Their ruling, expected within the next few months, may vindicate Sotomayor’s fears, taking the case’s principle far beyond a single church playground.

That’s a shame. For more than a century, courts have assumed that states can use public funds exclusively on public schools. But Trinity Lutheran suggests that, in fact, states may be obligated to spend public funds on private religious schools too—not just on playgrounds, but also on textbooks, and eventually tuition, through vouchers for sectarian institutions. Trinity Lutheran was the first wave in a constitutional sea change; Moses v. Ruszkowski could carry it further, and eventually, SCOTUS may take it to its logical conclusion by compelling states to provide vouchers for parochial schools. Roberts implied that his opinion had a narrow sweep. In reality, it is poised to sweep away a key barrier in the separation of church and state.