In a decision sparking immediate backlash from border hawks and Trump allies, a federal judge appointed by President Joe Biden has severely restricted the ability of U.S. Border Patrol agents to detain suspected illegal aliens without a warrant.

U.S. District Court Judge Jennifer Thurston, serving in California’s massive Eastern District, issued a preliminary injunction this week that bars warrantless arrests by Border Patrol unless agents can meet stringent new standards—including documenting in detail why a stop or arrest is being made and proving the individual poses an immediate flight risk.

Thurston’s order stems from a lawsuit originally filed against the Trump administration by the United Farm Workers union and represented by the American Civil Liberties Union (ACLU). The plaintiffs alleged that during Trump’s term, agents in Kern County and nearby areas engaged in a sweep that unfairly targeted Latino farm workers and day laborers, without regard to immigration status or probable cause.

Now, the Biden judge has turned that challenge into a sweeping restriction on federal immigration enforcement.

“Border Patrol is enjoined from conducting detentive stops in this District unless, pre-stop, the detaining agent has reasonable suspicion that the person to be stopped is a noncitizen who is present within the United States in violation of U.S. immigration law,” Thurston wrote, referencing the Fourth Amendment and long-standing constitutional requirements.

She also ruled that warrantless arrests can only occur if an agent has “probable cause to believe that the noncitizen being arrested is likely to escape before a warrant can be obtained.”

As if that weren’t enough, Thurston’s order mandates that agents provide detailed narrative reports for each warrantless arrest, laying out the specific reasons for the stop and the evidence leading up to it—before the arrest ever takes place. Those reports must then be submitted to the court every 60 days for review.

Critics say the decision essentially cripples field enforcement efforts in California, a key corridor for illegal immigration and human smuggling operations.

“This is a blatant attack on the ability of law enforcement to protect our border and enforce the law,” said one former Department of Homeland Security official, calling the ruling “unprecedented and politically motivated.”

The Trump administration had been ramping up enforcement across California before leaving office, citing the state’s sanctuary policies and failure to cooperate with federal immigration officers. The ACLU, however, claims the effort amounted to racial profiling and indiscriminate enforcement—accusations flatly denied by DHS at the time.

Former ICE Acting Director Tom Homan, now a member of the Trump White House team, blasted the ruling in an interview. “Illegal immigration is not a victimless crime,” he said. “Every time a Border Patrol agent is handcuffed by a judge like this, the cartels win. The traffickers win. And our communities lose.”

Homan pointed to recent data showing a sharp decline in illegal crossings under Trump’s second term policies—down nearly 99.99% from Biden-era highs—and warned that judicial activism like this could unwind that progress.

The ruling also comes amid growing legal resistance to Trump’s renewed immigration crackdown. The president has signed a series of executive orders empowering ICE and Border Patrol agents to pursue interior enforcement more aggressively, but those policies are increasingly being challenged in left-leaning states and courts.

What makes Thurston’s decision particularly striking is its scope. The Eastern District of California covers some of the most heavily trafficked parts of the state, including vast agricultural areas that have long been magnets for illegal labor. Under the new rules, agents working those areas will face extraordinary bureaucratic burdens before taking any action.

“Instead of deterring illegal crossings, the Biden bench is now making it easier,” said a spokesperson for a major border enforcement advocacy group. “This is what happens when you put open-borders radicals on the federal bench. They make national security decisions from the comfort of their chambers.”

While the Department of Justice has not yet indicated whether it will appeal the ruling, Trump officials and immigration advocates are calling on the administration to take action—and fast.

“This isn’t just a California problem anymore,” one official warned. “If this decision stands, it will be cited across the country. And that could spell the end of proactive immigration enforcement as we know it.”

With border agents already stretched thin and state cooperation in decline, this ruling adds yet another layer of complexity—and controversy—to the nation’s ongoing fight over who enforces America’s borders.