San Francisco, Santa Clara County and voting-rights groups planned to ask a federal judge in Oakland on Monday to block the Department of Homeland Security from sending armed agents to people's homes over a contested list of alleged noncitizen voters, The Sacramento Bee reported.

Why it matters:

  • The same data underpins the Justice Department's lawsuit seeking to set aside more than 20,000 California mail ballots ahead of Nov. 3.
  • Plaintiffs say the matching process produces many false positives among naturalized citizens and mixed-status households.
  • San Francisco and Santa Clara are co-plaintiffs, with City Attorney David Chiu and Santa Clara County Counsel as co-counsel.

What the lawsuit seeks

The case, California Nurses Association v. Mullin, was filed Sept. 18 in the U.S. District Court for the Northern District of California. Plaintiffs include the California Nurses Association, National Nurses United, Voto Latino Foundation, the City and County of San Francisco and the County of Santa Clara, according to Protect Democracy, which is co-counsel with the National Immigration Law Center.

They allege DHS built target lists by matching agency records against public state voter files, then directed ICE and Homeland Security Investigations agents to conduct in-person interviews at homes. The complaint says that practice violates Section 11(b) of the Voting Rights Act, the constitutional right to vote and the Administrative Procedure Act.

"This unlawful tactic is textbook voter intimidation weeks before an election — by a federal agency no less," Chiu said in the Protect Democracy release. "DHS is relying on flawed data to conduct field investigations designed to intimidate eligible voters in our diverse communities."

The Monday hearing and the 300,000 figure

The Sacramento Bee reported that lawyers planned to ask U.S. District Judge Araceli Martínez-Olguín for a preliminary injunction barring the government from using the list to target individuals. In a brief filed late Friday, lead attorney Beau Tremitiere wrote that the government had assembled a list of about 300,000 people that included many U.S. citizens and planned to send hundreds of investigators into the field, the Bee reported.

Social media posts from Homeland Security Investigations, included with the injunction motion, show agents approaching homes and say HSI in Northern California "will investigate any allegations of non-citizen voting," according to the Bee.

Related: DOJ's lawsuit over California's mail ballots and our Election 2026 hub.