A federal judge in California blocked the Department of Homeland Security from conducting most election-related field operations and interviews in nine states as part of efforts to identify noncitizen voters.

U.S. District Judge Araceli Martínez-Olguín, appointed by former President Biden, issued the ruling Wednesday. The order applies to California, Connecticut, Georgia, Missouri, Nevada, New York, Pennsylvania, Washington, and Wisconsin. It prohibits operations involving persons whom agents know, suspect, or should reasonably know or suspect are U.S. citizens.

The injunction stems from a lawsuit filed by the California Nurses Association, National Nurses United, and other groups. Plaintiffs argued the operations, part of the Trump administration's Unlawful Voter Initiative, risked intimidating voter mobilization efforts in violation of the Voting Rights Act.

Judge Martínez-Olguín found a high likelihood of error in the government's target lists, which rely on federal immigration data, state voter rolls, and commercial files. She noted no comprehensive federal database tracks citizenship status for all residents and highlighted time pressures on agents during reviews.

The ruling takes effect through polls closing on Election Day, November 3. The judge stayed the injunction until 5 p.m. Friday to allow the administration time to appeal.

The Trump administration has described the initiative as necessary to remove ineligible noncitizens from voter rolls and protect the integrity of federal elections. DHS officials stated they have no plans to question individuals believed to be U.S. citizens.

The operations involve hundreds of agents deployed to investigate suspected unlawful voting ahead of the midterms. The judge's order does not prevent investigations into confirmed noncitizens or other lawful enforcement actions.

This decision adds to ongoing legal challenges over federal efforts to verify voter eligibility using immigration records. Similar disputes have arisen in prior election cycles regarding the accuracy of citizenship data.