Experts say the ensuing judicial dust-up it will clarify precedent in a murky corner of the law. But some warn it could also unearth a road map for future deployments in cities across the U.S.

“If Breyer sides with Newsom and the 9th Circuit sides with Trump, we now have a playbook to use the National Guard and maybe the military around the country,” said Mark P. Nevitt, a law professor at Emory University and one of the country’s foremost experts on the law at the heart of the case.

“He’d have a ruling from the most liberal circuit in America giving the legal go-ahead for this deployment,” Nevitt said. “That would make bad law for the country.”