A sweeping campaign by federal immigration agents to identify voter fraud by noncitizens through door knocks, street stops and other field interviews in California and eight other states must be reined in ahead of the Nov. 3 election, after a federal judge in Northern California ruled it has intimidated U.S. citizens and interfered with the work of voting rights groups.

Judge Araceli Martínez-Olguin said in a ruling Wednesday that limiting the Department of Homeland Security's surging operations in those states — which she wrote "sweep in U.S. citizens for investigation" — does not prevent the Trump administration from "exercising their authority to investigate voter fraud by lawful means." A Homeland Security spokesperson said the agency is "laser focused on identifying, prosecuting, and removing aliens who vote," and has "no plans to question or investigate people we believe to be U.S. citizens."

The ruling was the latest to come out of an unprecedented legal war playing out between the Trump administration and California in recent days, in which an array of election cases are working their way through the federal courts at breakneck speed. There is, for example, the lawsuit the U.S. Justice Department filed against California and state and local elections officials last week, demanding that they set aside any ballots from a list of 20,000 individuals identified by immigration officials as "likely noncitizens." There are also two cases out of Washington, D.C., in which a coalition of Democratic leaders, immigrant rights groups, voting rights experts and naturalized citizens in California are challenging the Trump administration's use of Homeland Security data to target voters.

The litigation is playing out amid an intense political debate about election security at the national level — driven in part by President Trump, a longtime election denier — and a sweeping campaign by his administration to root out and parade examples of alleged voter fraud in the final days before the election. White House, Homeland Security and Justice Department officials have all defended the administration's efforts as necessary to ensure that noncitizens are not illegally diluting the votes of U.S. citizens. First Assistant U.S. Atty. Bill Essayli, the lead federal prosecutor in Los Angeles, has claimed to have "overwhelming evidence" that tens of thousands of noncitizens are doing so in California.

Democratic leaders and prominent elections experts, meanwhile, have cast the administration's claims as baseless and intentionally exaggerated to stoke uncertainty about election security and ultimately challenge midterm results the president doesn't like, and the Justice Department's legal arguments as fundamentally flawed and wildly out of line with long-established department policy to stay out of elections in the lead up to voting. "That is not normal. We have literally never experienced that in American history. Not once," said David Becker, executive director of the nonpartisan Center for Election Innovation & Research and a former Justice Department elections attorney.

"The fact that the administration appears poised for the first time to act as an adversary to the states and counties who have [the] undisputed constitutional authority to run elections? That is unusual." At the same time, Becker and other experts stressed that those efforts to date have failed, and state and local elections have largely proceeded in recent weeks without incident, with millions of Americans having already cast their ballots.

"California voters need to know that they're in good hands, that we have leaders at the state and local levels who are protecting our ballots and are ensuring that these attempts by the federal government to root out supposed noncitizen voting are not going to prevent Californians from casting our ballots," said Kim Alexander, president of the California Voter Foundation. "Part of the strategy here is to distract people and scare people and raise fears, and the important thing is to continue to stay focused on ... making a plan to vote."

Federal courts have already rejected multiple Trump executive orders seeking to enforce nationwide voter ID and citizenship requirements. The Supreme Court blocked an administration plan for the U.S. Postal Service to vet mail ballots. The Justice Department has compiled a stunning record of losses in its 30 lawsuits demanding state voter rolls — with 26 of those cases, including the one in California, so far dismissed. And election experts said they expect the Trump administration to rack up more losses in coming days — including in the Justice Department's case challenging California officials' refusal to segregate the ballots of some 20,000 voters based on the administration's unsubstantiated claims they are noncitizens.

That case was taken up — and scheduled for a Tuesday hearing — by Judge David O. Carter, an appointee of President Clinton who in January rejected the administration's demand for California's voter rolls, calling it a clear federal overreach that would have a "chilling effect" on voters and threaten American democracy. California has called for the case to be dismissed outright, on the grounds that the administration has zero authority to make such demands, and that the demands are unlawful. The Trump administration has asked Carter to immediately rule in the matter.

"Every minute of [ballot] processing that occurs without segregating the ballots of suspected non-eligible voters causes untraceable disenfranchisement and dilution of the votes of United States citizens," wrote Julie Hamill, an assistant U.S. attorney in Essayli's office. In D.C. federal court, Judge James E. Boasberg set an Oct. 30 hearing in a case in which UCLA Voting Rights Project attorneys, the Coalition for Humane Immigrant Rights, or CHIRLA, and a California voter named Pedro Trujillo are challenging the administration’s use of unproven federal databases to allege California voters aren't citizens.

Carl Bergquist, an attorney for CHIRLA, said he looked forward to bringing a host of recent Trump administration actions to the court's attention — including the administration's lawsuit against California, the charging this week of 28 legal permanent residents in California with election-related crimes, and Trump's threats to arrest California elections officials who don't comply with his administration's demands. "The events of the last few days, from threats to state and local officials, increased general immigration operations, the random knocking on doors by federal agents and the recent arrests are causing a chill in the community," Bergquist said.

"People, including naturalized citizens, are making their plans to vote and the Federal Government is doing its utmost to quash their attempts to exercise this fundamental right that they have lawfully acquired." The argument that naturalized citizens are being intimidated also features prominently in a second lawsuit filed in D.C. federal court Tuesday, in which top Democrats in Congress joined Nevada party officials and a California immigrant named Erick Jose Jimenez to challenge the Trump administration's unprecedented voter fraud probes.

That lawsuit, also assigned to Boasberg, says Jimenez, a naturalized citizen since 2006, fears being "unlawfully targeted for voting and disenfranchised (or worse)." Justin Levitt, a Loyola Law School professor who studies elections and was a senior policy advisor on democracy and voting rights in the Biden White House, said there is "so much noise" around the election right now, in part because the administration has been making wild legal arguments about its authority over elections.

But he said "none of the federal government's attempts to assert power that they do not have are working," and voting "for 99.999% of the public" will remain "wonderfully normal."