The case, "one of the biggest on church and state in a generation," could now hinge on whether five conservative justices agree that charter schools are "private entities seeking public grants rather than extensions of the public school system,

The Supreme Court is weighing the fate of a religious charter school in a blockbuster case that could alter the legality of such schools across the country.

Justices heard arguments for and against St. Isidore, a proposed Oklahoma school that would become the nation's first religious charter school.