The DOJ sued over claims the state hasn't purged noncitizens from voter rolls. By Juhi Doshi, Alexander Mallin, Luke Barr, Lucien Bruggeman The Trump administration is escalating its feud with California over allegations of noncitizen voting, threatening on Friday to criminally prosecute election workers who knowingly tabulate ballots belonging to noncitizen voters.

"The legal consequences for either facilitating or ignoring a federal crime are significant," Trent McCotter, the acting deputy attorney general, wrote in a letter to Los Angeles officials. "Noncitizen voting in a federal election is a federal crime--and knowingly facilitating such conduct is equally unlawful."

McCotter continued: "If persons knowingly tabulate ballots cast by individuals identified by federal agencies as noncitizens, they risk becoming aiders and abettors to a federal crime."

President Donald Trump reposted the letter to his social media platform. In a follow-up post resharing the letter, Trump wrote "They will all go to jail for a long period of time!!!"

The Justice Department's threat to hold election workers criminally liable for noncitizen voting is not the Trump administration's first such salvo. Over the summer, Homeland Security Secretary Markwayne Mullin similarly warned that election officials "can be held accountable by fines, by penalties, and even depending on how far it goes, prison time." Trump has made the issue of noncitizen voting a personal fixation despite scant evidence that it is widespread.

The Justice Department has promoted dozens of arrests in recent weeks of alleged noncitizens who have voted in past cycles. But even those examples fall far short of the sort of figures that would tilt the scales in any outcomes.

McCotter's threat to prosecute local election officials comes one day after the DOJ sued California over claims that the state has refused to purge noncitizens from its voter rolls.

Earlier this week, McCotter sent letters to the Los Angeles County Clerk and California Secretary of State demanding California voting officials access a password-protected thumb drive that DOJ officials said contained thousands of names of potential non-citizens believed to be on the state's voter registration list.

The letters gave a two-day deadline for the officials to confirm they were conducting a review and also moving to segregate any potential ballots that may have been returned from individuals whose names were on the thumb drive.

California characterized the request as legally baseless and a last-ditch effort by the Trump administration to intervene in the state's election process.

"The USDOJ's relentless efforts to unlawfully gain access to states' protected voter data and purge voter rolls serve only to cause chaos and fuel public distrust in our elections," California Secretary of State Shirley Weber said.

Experts overwhelmingly agree the lawsuit is unlikely to succeed. But they fear the consequences of publicly calling election outcomes into question could damage confidence in democracy.

Sean Morales Doyle, a voting expert at the Brennan Center, told ABC News on Friday that the Trump administration appears to be "laying the groundwork to challenge results after Election Day." "They're putting a nail in the wall for something to hang their hat on later," Morales Doyle said.