In an extremely important church-and-state decision, the Supreme Court has held that if the state of Maine decides to pay for a child's private education in lieu of a public one, it must allow its tuition money to be used at religious schools. The 6-3 decision, Carson v. Makin, profoundly undermines existing First Amendment law.
It represents the end of the centuries-old constitutional ban on direct state aid to the teaching of religion. And remarkably, it does all this in the name of religious liberty, giving the free-exercise clause of the First Amendment primacy over the establishment clause found in the exact same amendment.
The framers' conception of the two religion clauses of the First Amendment had two parts that fit together. The establishment clause meant the government couldn't make you perform a religious act or spend taxpayer dollars on religion. The free exercise clause said the government couldn't stop you from performing a religious act, understood as prayer or preaching or teaching or belief. (I wrote a book and several articles supporting this understanding of the history.)
For most of U.S. history, the Supreme Court enforced these clauses by, among other things, saying the government could not fund the teaching of religion in religious schools. That principle was substantially undermined 20 years ago when the court held that states could fund religious education -- including Catholic schools -- indirectly via voucher programs that could be used at secular or religious private schools.
But until this week, the Supreme Court didn't go the next step, which has been sought by advocates of religious education ever since. It had never held that if the state pays for private secular education, it must -- not may -- also pay for religious education. The key case holding the line was a 2004 decision, Locke v. Davey. In that ruling, the court said the state of Washington did not have to allow a student to use a state scholarship to pay for religious training in a religious institution.
The opinion by then-Chief Justice William Rehnquist said there was "play in the joints" between the two religion clauses. That meant the states could choose not to pay for religious education without the court saying the choice amounted to a violation of the religious liberty of the person who wanted to get religious education paid for.
Chief Justice John Roberts has managed to keep the Locke case alive while weakening its play-in-the-joints theory. The way he did it was by holding, in two recent cases, that the state can choose not to fund a specific religious action, but cannot exclude an institution from getting government funds because of its religious character. The distinction is subtle, even Talmudic. But it saved Roberts from having to overturn the Locke precedent.
In the Carson case, Roberts never specifically repudiated the play-in-the-joints idea. But even though he didn't reverse Locke v. Davey, he wrote an opinion under which the idea no longer makes much sense. Effectively, he overturned Locke without saying so.
The Maine law in question is applied so the content of the religious education matters. The state won't allow tuition to go to a school if it is associated with a particular belief system and promotes that belief system by teaching it "through the lens of faith." The analogy to the state of Washington's rule in Locke v. Davey is almost exact.
Roberts, however, characterized the Maine rule as discriminating against certain schools because of their "religious character." Such discrimination violates the free-exercise clause under the doctrine Roberts has developed. He held Maine must therefore let its state tuition aid go to the religious schools.
In dissent, Justice Stephen Breyer pointed out that play-in-the-joints was now a thing of the past. "The court today nowhere mentions, and I fear effectively abandons, this longstanding doctrine," he wrote. And in a passage destined to be cited by future litigants, he raised the most worrisome prospect of what is coming next: Does the holding 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?"
If the answer to Breyer's question were to be yes, Carson v. Makin would be a sea change in how education is financed in the United States. It would mean that states would have to fund Catholic schools, yeshivas and madrasas so long as the state pays for public schools.
On its face, the Carson decision doesn't go that far. Maine's provision is relatively unusual, stemming from the rural nature of the state, where some towns can't afford their own schools.
But Breyer's worry is real. The next step for religious schools will be to demand universal funding. And since this was a 6-3 decision, Roberts's vote wouldn't be necessary to reach the radical, topsy-turvy conclusion that, under the free-exercise clause, states must pay for religious education.
In a separate dissent, Justice Sonia Sotomayor put it bluntly: "Today, the court leads us to a place where separation of church and state becomes a constitutional violation." She's right, or very nearly so.
Under the Supreme Court's logic, for state government to avoid violating the establishment clause by refusing to fund religious teaching counts as a violation of the free-exercise clause. The framers would have been dumbfounded.
Noah Feldman is a Bloomberg Opinion columnist. A professor of law at Harvard University, he is the author, most recently, of "The Broken Constitution: Lincoln, Slavery and the Refounding of America."