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.

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.

In a 4-to-4 decision, the court upheld a ruling by the Oklahoma Supreme Court that blocked the school. An evenly divided Supreme Court rejected a plan on Thursday to allow Oklahoma to use government money to run the nation’s first religious charter school, which would teach a curriculum infused by Catholic doctrine.