The U.S. Department of Justice has sued California election officials, escalating a high-stakes dispute over voter eligibility just weeks before the November 3, 2026, midterm elections.

Filed Thursday in federal court in Los Angeles, the lawsuit seeks to prevent the state from counting mail-in ballots from more than 20,000 voters whom the Trump administration alleges may be noncitizens, until their citizenship status can be verified. The allegations have not been independently established in court.

California officials have pushed back, arguing that the federal government has not provided sufficient evidence or a transparent explanation for its list. State and local election officials warn that withholding ballots based on unverified information could affect eligible citizens.

The case highlights a growing conflict over federal oversight of elections and states’ authority to administer voting. Although federal law prohibits noncitizens from voting in federal elections, election administration is primarily handled by state and local authorities.

With control of Congress at stake, the lawsuit could have significant implications for election procedures, voter confidence and legal battles over mail-in voting. The court’s response will determine whether the requested restrictions can take effect before Election Day.