WASHINGTON — The Trump administration sued California on Thursday, seeking to stop the state from counting mail ballots from more than 20,000 registered voters it suspects are noncitizens.

The Justice Department wants officials to set aside those ballots until the voters’ citizenship can be verified. The lawsuit, filed Oct. 15, brings the dispute into federal court just 19 days before the Nov. 3 midterm elections.

California officials dispute the basis for the demand. Secretary of State Shirley Weber says the federal government has not provided adequate supporting evidence and is asking the state to jeopardize voting rights based on unverified information.

The case could affect voters well beyond Los Angeles County. Although the federal government delivered its list to the county’s election office, county officials say it includes names from across California.

What DOJ wants California to do

According to the Justice Department’s announcement, federal officials identified the voters through a review involving immigration authorities and voter-registration records.

The department says California failed to work with federal agencies to establish whether the listed people are citizens. It wants officials to verify their status before counting their mail ballots, rather than relying solely on citizenship statements made during registration.

The requested restriction would apply to ballots from the identified voters. It is not a request to stop California’s entire election or all mail-ballot counting.

Attorney General Todd Blanche characterized the dispute as an election-integrity issue.

“State-facilitated voter fraud is unacceptable in the United States of America,” Blanche said in the department’s statement announcing the lawsuit.

However, the same announcement describes the federal analysis as preliminary and ongoing. Homeland Security Secretary Markwayne Mullin said agencies compared voter-registration information with federal immigration records to identify people they consider likely noncitizens.

A thumb drive and a 48-hour deadline

The confrontation escalated after federal officials contacted California election authorities Oct. 13.

Los Angeles County Registrar-Recorder/County Clerk Dean Logan said his office received a USB drive purportedly containing the records, along with a handwritten password. In an Oct. 14 statement, he said the office had not accessed it because doing so would conflict with established privacy and information-security procedures.

Logan also said the accompanying letter did not specify how many people were involved or describe the records. His office was reviewing the correspondence with state officials, he said, while continuing to administer the election.

Meanwhile, Weber said DOJ demanded action within 48 hours. Her office had not received the voter list directly, she wrote in her response to federal officials.

She questioned how the state could obtain the information, investigate approximately 20,000 people and confirm their citizenship within that period.

“This is an emergency of the DOJ’s creation,” Weber wrote.

How federal agencies say they identified the voters

The federal complaint describes several stages of review.

U.S. Citizenship and Immigration Services compares voter information with internal records and uses third-party software to supplement incomplete data. The agency then evaluates the strength of matches and checks for evidence of naturalization or citizenship acquired through other means.

According to the complaint, officials also consult State Department records and conduct a second-level review. Homeland Security Investigations then performs additional analysis and investigative work.

Those descriptions are the government’s account of its methods. California officials dispute whether they received enough underlying information to evaluate the resulting list.

The complaint also says this California review occurred independently of the Systematic Alien Verification for Entitlements program, known as SAVE. That distinction is relevant because separate litigation has challenged federal reliance on that database.

Los Angeles County challenges the evidence and scope

After DOJ filed suit, Logan said the county had already submitted a formal response outlining its concerns.

In his Oct. 15 statement, Logan said the government’s list included people outside Los Angeles County. His office has no authority to act on those voters’ records, he said.

He also challenged the suggestion that county officials had simply ignored the federal demand. DOJ filed its lawsuit without acknowledging the county’s timely response, Logan said.

The county remained responsible for both accurate registration records and eligible voters’ access to the ballot, he added.

“We cannot withhold or refuse to count ballots based solely on unverified allegations,” Logan said.

He said DOJ had not provided the underlying evidence, sources or methodology supporting its claims that the listed people were ineligible.

Weber likewise said California would review substantiated evidence and take appropriate action under state and federal law. However, she rejected withholding votes based solely on the government’s stated belief about citizenship.

What federal election law says

Federal law generally prohibits noncitizens from voting in elections for federal office. The relevant criminal statute, 18 U.S.C. § 611, covers elections for president, the Senate and the House, among other offices.

The law distinguishes those contests from certain state or local elections that separately authorize noncitizen participation. Such authorization does not permit noncitizens to vote for federal candidates. The statute also contains a narrow exception involving certain people who reasonably believed they were citizens.

DOJ argues that California is facilitating conduct prohibited by federal law and invokes the Constitution’s Supremacy Clause. Its complaint seeks an injunction against counting the specified mail ballots until citizenship is verified.

California raises a separate protection: the National Voter Registration Act’s 90-day restriction on systematic removals from voter rolls.

The Justice Department’s own voter-list maintenance guidance explains that states must complete such programs at least 90 days before a federal primary or general election.

That restriction has exceptions. It does not prevent removing someone at their request or because they have died. Certain removals based on criminal convictions or mental incapacity under state law also remain permissible, as do corrections to registration information.

Weber argues that treating thousands of registered voters as ineligible until they prove otherwise violates that protection. The court dispute therefore involves both the evidence concerning citizenship and the government’s authority to obtain the requested restrictions during an election.

Related coverage: Trump Mail-In Voting Order Heads to Supreme Court Before 2026 Midterms

An earlier ruling adds another legal question

The California lawsuit follows an Oct. 9 ruling against a separate Justice Department voter-list policy.

In Common Cause v. U.S. Department of Justice, U.S. District Judge Sparkle Sooknanan rejected a policy involving the collection and sharing of state voter rolls and demands for removals based on federal database comparisons.

The judge found that the policy exceeded statutory authority and violated federal administrative and privacy requirements. She also faulted officials for failing to adequately consider the danger of misidentifying eligible citizens.

The opinion described cases involving U.S. citizens whose Texas registrations were canceled after database checks failed to confirm their citizenship.

However, the ruling did not prohibit lawful federal assistance with voter-list maintenance or prevent states from maintaining accurate records.

Weber says the latest federal demands may conflict with that decision. DOJ’s statement that its California review operated independently of SAVE is one distinction the new litigation raises. The earlier ruling did not decide the merits of this subsequently filed California lawsuit.

Nevada illustrates the dispute over database matches

A similar disagreement has already unfolded in Nevada.

According to Reuters’ Oct. 15 reporting, federal officials initially raised concerns about nearly 16,000 possible noncitizens on that state’s rolls.

DHS later told Nevada officials it had confirmed 185 cases. But Nevada officials said their records showed all 185 were citizens and that DHS had provided nothing substantive establishing otherwise.

That dispute does not determine whether California’s list is accurate. It does show why state officials are demanding supporting records before acting on federal citizenship flags.

What California voters should know

California’s election calendar continues while officials contest the federal demands.

The state’s voting information page provides instructions for returning ballots and access to its “Where’s My Ballot?” tracking service. Tracking can help voters monitor their ballot’s progress and identify issues requiring attention.

The regular online voter-registration deadline for the Nov. 3 election is Oct. 19, according to the secretary of state’s registration guidance. California also provides a conditional-registration process for eligible people who miss the regular deadline.

For voters concerned about their own records, county election offices remain the official point of contact. Logan said his office would continue following established procedures to protect eligible voters and count valid ballots.

The immediate question is whether federal officials can obtain a court order withholding the challenged ballots. Their allegations alone do not establish that the people on the list are ineligible—or that their votes must be excluded.