The fight over California's voter rolls escalated on Tuesday, October 20, as the state and Los Angeles County filed court papers opposing the U.S. Department of Justice's demand that ballots associated with about 20,000 people the department calls "likely" noncitizens be segregated and not counted until their citizenship is checked, according to NPR and MyNewsLA, which reported on the filings.

The Justice Department sued California last week after delivering the list — first on a thumb drive, which county officials initially declined to plug in over security concerns, and then as a spreadsheet — of roughly 20,000 registered voters whom Department of Homeland Security investigators say are likely noncitizens. Only 7,035 of the names had addresses in Los Angeles County, and some were duplicates, according to a filing by Los Angeles County Registrar Dean Logan reported by NPR.

Los Angeles County officials told the court they sampled 200 people from the list. Assistant Registrar-Recorder Monica Flores wrote that the review is preliminary but "indicates that the October List is unreliable." Of the sampled voters whose birthplace was meaningfully reported, 38.9% indicated they were born in the United States — which NPR noted is strong evidence of citizenship. The filing also said 112 of the 200 sampled registrations were cancelled or inactive, and about 70% of those sampled had no voting history. In a separate 41-page opposition reported by MyNewsLA, county attorneys argued there is no credible evidence to support the claim of large-scale noncitizen voting.

The state argued that complying so close to the election would be unfeasible and would likely break federal and state election laws. "At best, this litigation is a reckless political stunt," the state wrote in Tuesday's filing. "At worst, it threatens to disenfranchise thousands of Californians this election."

The Justice Department has defended its list while conceding it may not be perfect. Acting Deputy Attorney General Trent McCotter acknowledged at a Monday press conference that there could be some errors: "There may be some names on there who it turns out ultimately are citizens, we're not perfect," he said, adding that this was why the department asked California to cooperate. DOJ deputy press secretary Kiersten Pels said in a statement, reported by NPR, that "California cannot facilitate the violation of federal law" and that the department had asked the state to independently verify the citizenship of any ballots cast by people on the list.

Voting is already under way in California for the November midterms, and the court has yet to rule on the federal request. For the state's large immigrant and diaspora communities, the case is being watched closely: election officials in California ask for place of birth when people register online, though the field is not mandatory, and anyone born in the United States is a citizen. (Sources: NPR via WESA/KNKX, MyNewsLA, and the court filings cited in that reporting.)