An Oklahoma board approved the nation’s first religious charter school, agreeing to publicly fund a school where Catholic teachings will be incorporated into lessons throughout the day — and testing the constitutional bounds of taxpayer funding for religious education.

The new online school was created in part to provide Catholic education for students in rural areas that do not have a private Catholic school nearby. The school, which will enroll students in grades K–12, was set up intentionally to test the legal limits of taxpayer funding for religious schools.

“This decision runs afoul of state law and the U.S. Constitution. All charter schools are public schools, and as such must be nonsectarian,” said Nina Rees, the president and CEO of the National Alliance for Public Charter Schools, an advocacy group. “The Archdiocese of Oklahoma City is trying to make charter schools into something they are not.”

The move is part of a conservative push to expand the boundaries of school choice, giving families more taxpayer-funded options for religious education.

A drive to break down the once-solid wall between public funding and religious education has already made significant gains. Over the past six years, a conservative U.S. Supreme Court has issued three rulings that religious institutions could not be excluded from taxpayer-funded programs that were available to others.