Gavin Newsom’s legislative minions just got a lesson in constitutional supremacy

California's "No Vigilantes Act" looked airtight on paper. Passed in 2015 and tightened in 2017, the law prohibited state and local law enforcement from assisting Immigration and Customs Enforcement agents—blocking collaboration on immigration enforcement unless ICE had a judicial warrant signed by a judge. The legislative intent was clean: stop raids, protect immigrant communities, weaponize California's police apparatus against federal immigration enforcement. Governor Newsom championed it as a shield for vulnerable populations. The Ninth Circuit just ran it through a constitutional wood chipper.

The three-judge panel's decision, released this week, was unanimous and brief on the fundamentals: when federal law conflicts with state law, the Constitution's Supremacy Clause wins. Full stop. The court found that California was attempting to regulate federal agents in the performance of federal duties—territory the Constitution reserves exclusively to Washington. It didn't matter that the law was framed around state police conduct rather than direct federal prohibition. The practical effect was the same: preventing ICE from doing its job on California soil. That crosses the line from state autonomy into federal power territory.

Here's what actually changes on the ground. ICE can now compel California law enforcement to cooperate with immigration enforcement operations, or at minimum, remove the legal obstacle that made cooperation impossible. Federal agents won't need judicial warrants to enter California courthouses, hospitals, or schools to detain people—the primary worry that drove the law's supporters. Immigration advocates who built years of strategy around California as a sanctuary state just lost their most powerful legal tool. The practical leverage California thought it had is gone.

The conservative argument here doesn't require exaggeration: Congress passed immigration law. The Constitution gives the federal government exclusive power over immigration and foreign relations. California's legislature tried to nullify federal statute by making it impossible to enforce. That's not federalism—that's states saying "we'll pick which federal laws we feel like allowing." If every state did this with environmental law, tax law, securities law, the entire federal system collapses. Newsom's legislature wrapped this in sanctuary rhetoric, but constitutionally it was nullification with better PR.

The mechanism matters for what's next. This wasn't a ruling on immigration policy's wisdom or whether ICE tactics are good. It was jurisdictional—about who gets to make the call. But it does mean Biden administration officials could have pressed harder on enforcement cooperation rather than deferring. And it signals how hostile any future federal administration might be to state-level resistance to federal law enforcement actions, immigration or otherwise. The Trump administration, if it wins in 2024, could cite this exact precedent when telling sanctuary cities their legal foundations have crumbled.

Watch for California's likely appeal to the full Ninth Circuit, though the unanimous three-judge panel decision makes that uphill. More immediately, watch whether California's attorney general actually enforces the ruling or tries to find workarounds—directing police not to cooperate while technically complying with the court order. That's the actual showdown: whether a state can technically obey a constitutional ruling while practically undermining it through policy guidance. The Supremacy Clause won round one. Round two is whether it actually means anything on the ground in Sacramento.