The U.S. Department of Justice has thrown its support behind a small group of Maine parents who have filed a federal lawsuit seeking reimbursement for their children’s religious school tuition.

The department filed a “letter of interest” in U.S. District Court in Portland on Monday expressing its opinion about the Maine case, Carson v. Makin. It sided strongly with the plaintiffs, citing DOJ guidance that “government may not target persons or individuals because of their religion,” and “individuals do not give up their religious-liberty protections by providing or receiving social services, education or healthcare.”

Three married couples in central Maine filed the lawsuit in August 2018 against the state Department of Education over a decades-old Maine law that bars tuition reimbursements for religious schools. Oral arguments in the lawsuit are scheduled for June 24 at the federal courthouse in Portland.

Local school administrative units in Maine that do not have their own secondary schools can pay a certain amount in tuition for students to attend outside public or private schools. But that money cannot be used at religious schools, a policy that the parents’ legal complaint calls discriminatory and unconstitutional.

The plaintiffs, led by Glenburn residents David and Amy Carson, are represented by two national groups that describe themselves as advocates for religious liberty and school choice. The lawsuit comes at a time when the Trump administration has made the push for alternatives to public schools central to the national education policy debate.

DOJ spokeswoman Kelly Laco said in an email that the protection of religious freedom is a top priority for the department.

In July 2018, the DOJ announced the formation of the Religious Liberty Task Force, which brings together department components to coordinate their work on religious freedom litigation and policy, and to implement former U.S. Attorney General Jeff Sessions’ 2017 religious liberty guidance, Laco said.

“That guidance was issued at the direction of President Trump’s May 4, 2017, executive order promoting free speech and religious liberty,” she said.

Laco did not respond to a follow-up email asking if the Department of Justice plans to get involved further in the case, such as by participating in oral arguments.

Zachary Heiden, legal director for the American Civil Liberties Union of Maine, said his organization joined the case as a “friend of the court” arguing in favor of upholding the state’s ban on tuition reimbursement for religious schools.

Heiden said he has read the DOJ’s letter and found that its legal arguments primarily echo those made by the plaintiffs in their original complaint. He said it’s not unusual for the department to file a letter of interest in a case in which it has an opinion.

“This is what they do,” Heiden said. “This is one of the ways in which the Department of Justice does its job.”

He said the impact of the lawsuit’s outcome will be limited in scope because the existing law only applies to certain small communities in Maine. However, it could be used as precedent in other related cases.

Heiden believes the plaintiffs have an uphill battle. The same state law has been challenged four times in various state and federal courts, he said, and in all four cases the plaintiffs have lost.

“Those courts have always said that this Maine law is constitutional, is permissible,” Heiden said. “That law hasn’t changed. The First Amendment hasn’t changed. So it would be quite significant for the court to now say that, actually, the Maine law violates the Constitution.”

More than 30 states have constitutional amendments that prohibit state funding of religious organizations, including schools. Though Maine is not one of them, it passed a law in 1981 that bars public funding for sectarian schools. Legislative efforts to expand school choice and give taxpayer money to religious schools have failed to gain traction in recent years.

One of the groups representing the plaintiffs in Carson v. Makin, the Virginia-based Institute for Justice, a nonprofit libertarian public-interest law firm, has said it decided to challenge the Maine law again in light of a U.S. Supreme Court ruling in 2017.

In that case, Trinity Lutheran Church in Missouri was barred from participating in a state program that reimburses the cost of rubberizing playground surfaces. The nation’s highest court ultimately decided the church should be eligible for that public funding. Advocates for public funding of religious schools hope that case will serve as legal precedent to advance their own interests.

But Heiden said he doesn’t see a strong connection between the Missouri case and the one in Maine.

“I disagree with their interpretation of that (Missouri) case,” he said. “It’s about … shredded rubber tires on playground surfaces, which I don’t think is the same thing as funding education. But obviously the DOJ has a different interpretation of that.”