A split U.S. Supreme Court on Thursday blocked a bid led by two Catholic dioceses to establish in Oklahoma the nation's first taxpayer-funded religious charter school in a major case involving religious rights in American education.

The case, a major test of the separation of church and state, was an unexpected loss for religious rights advocates after a string of victories.

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.