AUSTIN, Texas (AP) — The Texas Supreme Court is hearing arguments in a case that conservatives hope will provide an opening to challenge the landmark 2015 ruling legalizing gay marriage nationwide.

The all-Republican court initially refused to hear the lawsuit, which challenged Houston's decision to offer same-sex spousal benefits to municipal employees. The court deferred to the U.S. Supreme Court declaring gay marriage constitutional.

But the court reversed itself last month amid pressure from Texas' governor, lieutenant governor, attorney general and leading religious and conservative activists. They argue that the case may help Texas limit the scope of the U.S. Supreme Court ruling, especially in how it's applied at the state level.

Houston officials argue the case is a matter of settled law that has nothing to do with advancing social conservative causes.