A voter drops a mail-in ballot into an official drop box inside City Hall during the primary election in San Francisco, California, Tuesday, June 2, 2026.
David Paul Morris | Bloomberg | Getty Images
The federal government sued the state of California on Thursday in an escalating battle over how to prevent non-Americans from voting by mail in federal elections.
The lawsuit is the latest action by the Justice Department to target the state’s election administration, which President Donald Trump has often criticized as susceptible to fraud and non-citizen voting.
The civil suit, which the Justice Department had threatened to file, asks a judge to prohibit California officials from counting mail-in ballots “from persons who are likely to be non-citizens in an upcoming federal election until the citizenship status of the voter is known.”
The Justice Department is asking a judge to order the state to withhold mail-in ballots from voters “who the federal government determines are likely to be non-citizens” and to verify citizenship before counting the votes.
Noncitizens are prohibited from voting in federal elections.
In a post on X on Wednesday, California Governor Gavin Newsom called the prospect of a lawsuit “yet more dangerous nonsense from a president who has lost his grip on reality.”
“Mr. Trump is now demanding that California election officials violate federal law,” Newsom wrote. “Clearly, the rule of law only matters when it suits MAGA’s dear leaders. California’s elections are not in Donald Trump’s control. We will ensure that every California voter can participate in free and fair elections.”
The lawsuit in U.S. District Court in Los Angeles comes two days after Acting U.S. Attorney Trent McCotter, in a letter to California Secretary of State Shirley Weber, gave the state 48 hours to determine whether a U.S. citizen is included on a list of people the Justice Department believes are likely noncitizens whose ballots were sent in for the Nov. 3 election.
The Department of Justice previously gave Los Angeles County authorities thumb drives containing the names they were questioned about.
McCotter told Weber that the state should instruct local election officials to sequester mail-in ballots until a voter’s citizenship status is known and not send a ballot to anyone who has not yet received one.
“Given the ongoing federal election, if this process cannot be completed by then, the United States will have no choice but to seek emergency relief,” McCotter said in the letter.
“In July of this year, President Trump and Secretary of Homeland Security Markwayne Mullen made the (still) unsubstantiated claim that there were 190,000 noncitizens on California’s voter rolls,” Weber’s office said in a statement Thursday.
“Given the many high-profile cases in which states have removed American citizens from their voter rolls based on DHS/SAVE data, SOS immediately requested written information regarding its methodology and data sources to support its claims,” Weber’s office said. “They refused and offered California nothing.”
“Now, the U.S. Department of Justice is threatening an ‘emergency’ lawsuit and asking California to blindly trust this administration with no evidence or legal authority to justify that request.”
Weber said in a statement Thursday that the Justice Department’s “relentless efforts to illegally access state-protected voter data and purge voter rolls only serve to sow confusion and fuel public distrust in elections.”
He also said California “has strict state law requirements that only U.S. citizens can register to vote and that ineligible registrants are removed from the state’s voter rolls.”
“My office and California election officials remain committed to ensuring that the 2026 general election is fair and smooth,” Weber said.
CNBC has reached out to Weber’s office for comment on the lawsuit.
