Just how unconstitutional is Newsom's ban on law enforcement masks?

Gov. Gavin Newsom has signed an ambitious package of bills aimed at reining in federal law-enforcement activity in California. But even if the measures survive court challenges, the state may struggle to enforce one of them.

The governor signed five bills on Saturday. The most legally fraught is SB 627, which, with limited exceptions, prohibits officers from wearing masks that obscure their faces--a practice that has become common during immigration sweeps in California and elsewhere.

"The mask mandate is the one that's questionable and probably not constitutional," said Leslie Gielow Jacobs, executive director of the Capital Center for Law & Policy at the University of the Pacific, McGeorge School of Law. She said SB 627 would be preempted by the U.S. Constitution's supremacy clause. "The state can say state and local police officers must abide by these mask rules," Jacobs added. "But the problem comes when they try to apply it to federal officials. If it undermines the purpose of federal law enforcement, then that will be a conflict, and California won't be able to apply its rule."

"I think the mask law is the one most likely to be challenged," Kevin R. Johnson, a professor at the UC Davis School of Law, wrote in an email. The Department of Homeland Security "called on the governor not to sign it. A legal challenge is uncertain. The law now includes a safety exception. ICE could wait to see if there is any enforcement."

Litigation may not come immediately. The masking provision does not take effect until July 2026. In a signing statement, Newsom said SB 627 "requires follow-up legislation when the Legislature returns in January."

The Peace Officers Research Association of California "is planning to address the issues we see with SB 627 during the next legislative session," its president, Brian R. Marvel, said in an email. "We do not believe the state can plausibly enforce SB 627 on federal officers." Marvel's organization represents more than 80,000 officers in hundreds of agencies.

In a Sept. 16 letter urging a veto, he wrote that while the group shares concerns about unidentified agents detaining people without proper process, SB 627 "does nothing to regulate federal activity and instead unfairly punishes California's local officers," calling the late-session bill "deeply flawed, unconstitutional, and dangerous to public safety."

The letter described failed talks with Sen. Scott Wiener (D-San Francisco) over late amendments and warned of "wildly different interpretations" and "a chilling effect ... driving existing officers out of California." It added: "Courts have consistently upheld (since Cunningham v. Neagle in 1890) that federal officers are immune from state prosecution for federal functions. ... President Trump will likely welcome this easy court victory."

"I'm committed to working with the governor's office to further refine SB 627 early next year to ensure it is as workable as possible for many law enforcement officers working in good faith to keep California communities safe," Wiener said in a Saturday news release.

Republican political consultant Mike Madrid, a frequent critic of his party's policies on illegal immigration, also doubts SB 627 is enforceable--so much so that the Trump administration may not bother to challenge it. "I think it's largely symbolic," Madrid said. "It's kind of like the U.N. saying something."

He added that it is unclear who would enforce the law, noting that many sheriffs have declined to enforce certain state measures. "The courts are going to have to ultimately decide it," he said. "I just don't see local law enforcement trying to arrest a group of masked ICE agents."

Johnson said the other bills Newsom signed are on safer footing. AB 49 prohibits immigration raids in nonpublic areas of schools. SB 98 imposes related protections for students, including at colleges and charter schools. SB 81 bars health care providers from sharing a patient's immigration status with federal authorities without a warrant. Jacobs said these measures resemble earlier laws that withstood court challenges. "We've been through this rodeo before with the first Trump administration. ... You can say, 'We're not going to help you,' but you can't do something that actually hinders what the federal government is doing," she said.