The Supreme Court split evenly Thursday in a high-profile challenge over the nation’s first religious charter school, leaving in place a ruling from Oklahoma’s top court that found the proposed Catholic school unconstitutional.

The Supreme Court deadlocked Thursday over the constitutionality of what would have been nation’s first public religious charter school, blocking the creation of a Catholic institution that would have reshaped American education and blurred the line between church and state.

The case, a major test of the separation of church and state, was an unexpected loss for those advocating a greater role for religion in public life.