PORTLAND – Maine’s law banning state funding of religious schools was appealed to the nation’s highest court on Tuesday.

The Maine Supreme Judicial Court ruled in April that restrictions on tuition vouchers continue to be a “valid, constitutional enactment.” The ruling marked the second time in a decade that the state supreme court upheld a 1983 law.

The Institute for Justice, which brought the challenge on behalf of eight families from Durham, Minot and Raymond, filed the appeal to the U.S. Supreme Court.

An estimated 17,000 Maine students from 145 small towns with no high schools are subject to the voucher program. School districts in those towns offer tuition for students to attend high schools of their choice, but religious schools are not on the list.

“Maine offers school choice to everyone except parents who choose religious schools,” said Dick Komer, lawyer for the Institute for Justice in Arlington, Va. “Under the federal Constitution, that’s religious discrimination.”

Before 1980, Maine’s tuition statute permitted payment of public funds to approved religious schools. But that ended with an advisory opinion by the attorney general that the practice violated the U.S. Constitution’s Establishment Clause. The current practice began in 1981, and the Maine Legislature made it law in 1983.

The Maine Supreme Judicial Court ruled that it’s legal to allow school voucher funding for religious schools and that it’s also legal, as the Maine Legislature did, to ban the use of public funds for religious schools.