Last week, the Supreme Court’s 6-3 decision in Carson v. Makin left advocates on both sides of the school choice debate navigating a new legal landscape.

The Court ruled that Maine’s exclusion of religious schools from a state tuition program was “discrimination against religion.” The program uses taxpayer dollars to help rural families who live far from a public school attend a private school instead.

Writing for the majority, Chief Justice John Roberts noted that while a state is not required to fund a private, religious school, if public funding is extended to secular, private schools it must also be extended to religious schools.

Up for debate now is what the broader effects of the ruling might be, as well as its impact on public school funding.

Jessica Levin, director of the advocacy campaign Public Funds Public Schools, said that the ruling currently applies only to Maine and neighboring Vermont and New Hampshire, where similar tuition programs already exist. It would not apply to any state operating a school voucher program.  

“In light of the Carson decision, a state cannot single out and exclude religious options from a program in which other programs are allowed to participate. In doing so, it is going to pave the way for many, many more school choice programs.”

Michael Bindas, lawyer for the Institute for Justice, which represented the lead plaintiffs

“The tuitioning programs are not vouchers. Vouchers are a separate statutory scheme to provide funding for an additional private school option on top of the public schools that are available for all and that is not the situation for these historic and geographic reasons in these three states,” said Levin.

Related: I got to choose private schools, but will vouchers really help other kids make it?

Michael Bindas, a lawyer with the Institute for Justice, who represented the lead plaintiffs, said that while it’s true the case will have the most immediate impact on the administration of programs in those three states, he sees the judgment having wider consequences.

“In light of the Carson decision, a state cannot single out and exclude religious options from a program in which other programs are allowed to participate,” said Bindas. “In doing so, it is going to pave the way for many, many more school choice programs.”

According to Bindas, the ruling nullifies no-aid amendments found in 37 state constitutions. Sometimes referred to as Blaine amendments, these provisions forbid public funds from going to private, religious institutions.

Bindas said the Carson decision removes the hurdle of no-aid amendments for states wishing to establish school choice programs.

“The legal cloud has been lifted and we are going to see many more state legislatures adopt these programs,” said Bindas.

But not everyone agrees with that interpretation.

“There are a lot of attacks on no-aid clauses that have not been successful,” said Levin.

Last year, the South Carolina Supreme Court rejected an attempt by a coalition of private colleges to strike down the state’s no-aid amendment, finding that the amendment did not spring from animosity toward religion and declined to strike it down.

“People recognize that we are always struggling to get enough money for our public schools and so people have enshrined in their state constitutions firewalls to keep that public money in public schools,” said Levin.

After Carson, Levin said public school advocates must prioritize educating state legislatures on the implications of school choice programs on the allocation of public dollars.

“If they are going to create a system where parents receive public school funds [for their kids] to attend private school, they are opening up a Pandora’s box for funding religion, for funding discrimination,” said Levin.

Public school advocates in Maine, Vermont and New Hampshire say they are also considering a new campaign to repeal or reform tuition programs to ensure that only public schools receive public dollars.

“We’re talking about a Supreme Court decision that forces taxpayers to send their tax dollars to a religious institution. It’s one more opportunity to siphon public dollars from public schools,” said Don Tinney, president of the Vermont chapter of the National Education Association, a national teachers’ union.

Tinney said he will encourage union members to press districts to remove any private school option — religious or secular — from their tuition programs.

“It’s important that our members be engaged on this issue,” said Tinney, “because the entire system is at risk.”

Also up in the air following the Carson decision is how future judges may interpret the tension between an individual’s religious rights under the First Amendment’s free exercise clause and a state’s anti-discrimination policy.

Related: Vouchers may be ticket out of public schools for kids with disabilities — but is that a good thing?

After the Supreme Court announced its decision, Maine Attorney General Aaron Frey issued a statement saying that any private, religious school receiving public dollars would be required to adhere to the anti-discrimination provisions found within the state’s Human Rights Act. Last year Maine legislators amended that law to explicitly forbid any publicly funded educational institution, including private schools receiving funds through the tuition program, from discriminating based upon gender identity or sexual orientation.

Two of the religious, private schools at the center of the Carson case — Bangor Christian School and Temple Academy — have explicit policies barring the admission of LGBTQ students or hiring LGBTQ teachers, according to court documents.

In his statement, Frey said schools participating in the state’s tuition program “must comply with anti-discrimination provisions of the Maine Human Rights Act and this would require some religious schools to eliminate their current discriminatory practices.”

That means despite the Supreme Court’s decision barring Maine from excluding religious schools from the state’s tuition program, schools that refuse to comply with the state’s anti-discrimination policy — such as Bangor Christian School and Temple Academy — would remain ineligible for public funding.

Dmitry Bam, who teaches constitutional law at the University of Maine School of Law, says that because Maine’s Human Rights Act is a generally applicable legal principle, religious institutions are ineligible for an exemption, but he says this principle could be tested.

“I think the area of law is in flux. I think the AG is right that currently under the law, a generally applicable legal principle applies to everyone, so there’s no religious exemptions that are required,” said Bam. “But the court seems to be skeptical of that line of reasoning and at least in recent cases have found ways to require states to provide those exemptions, so I expect it is an evolving area of the law.”

Lawyers on both sides agree that this tension could be taken up by the courts in the future. In last year’s decision Fulton v. Philadelphia, the court unanimously found that a religious foster care agency that declined to make referrals to LGBTQ couples was entitled to an exemption from a rule forbidding such discrimination because the city provided exceptions in its anti-discrimination policy.

In Carson v. Makin, the Court did not address the question of whether a religious institution can cite sincerely held religious beliefs to violate laws against discrimination.

“The law that we challenged turned solely on religion,” said Bindas.

“Are other cases going to come up down the road, where the interaction between school choice and anti-discrimination statutes is at issue? I suspect they will,” said Bindas. “How those cases will come out — I don’t know.”

In his dissent in Carson, Justice Stephen Breyer wrote that the ruling disregarded the long-respected “wall of separation” between church and state by requiring that Maine use taxpayer dollars to fund a religious intuition.

Following Carson, Bam said it’s conceivable that a religious private school, currently excluded from the tuition program under Maine’s anti-discrimination policy, could go to the courts to challenge the state’s policy by asserting their religious beliefs entitle them to an exemption.

“When you say that you are going to publicly fund schools that engage in discrimination, that’s not a victory for choice for families, that’s a choice for schools — that’s giving them the choice to discriminate, the choice to exclude students.”

Jessica Levin, director of the advocacy campaign Public Funds Public Schools

Such an argument would challenge the precedent established in Employment Division v. Smith, a 1990 case in which the Court found that generally applicable laws don’t require a religious exemption, even if the laws burden a religious practice. But Bam said the current court may be more sympathetic to a religious freedom argument.

“There are a lot of conservative justices who think that’s the wrong approach and that the states should be required to show some higher standard of proof before they take away an exemption,” said Bam. Justice Samuel Alito, a leader of the court’s new conservative majority, argued in concurrence in Fulton that Smith should be overruled.

For public school advocates like Levin, this possibility is further cause for alarm.

“When you say that you are going to publicly fund schools that engage in discrimination, that’s not a victory for choice for families, that’s a choice for schools — that’s giving them the choice to discriminate, the choice to exclude students,” said Levin.

This story about Carson v. Makin was produced by The Hechinger Report, a nonprofit, independent news organization focused on inequality and innovation in education. Sign up for Hechinger’s newsletter.