A federal appeals court on Tuesday spent more than an hour grappling with whether President Donald Trump unlawfully federalized thousands of members of California’s National Guard to beef up security in Los Angeles amid unrest over immigration enforcement there.

The 9th U.S. Circuit Court of Appeals has temporarily blocked a federal judge’s order that directed President Donald Trump to return control of National Guard troops to California after he deployed them there following protests in Los Angeles over immigration raids.

A federal judge ruled Thursday that President Trump illegally federalized the California National Guard in response to the Los Angeles protests and ordered that the force be returned to the control of Democratic Gov.