With one day remaining before the Nov. 3 election, the U.S. Department of Justice has asked the Supreme Court to intervene in its dispute with California over the state’s voter rolls. The department filed a notice Monday indicating that it plans to appeal lower-court decisions rejecting its request to stop processing certain ballots.

The DOJ says it identified 20,000 “likely” noncitizens on California’s voter rolls and argues that their ballots should be withheld until their citizenship is verified. A federal district judge and a divided panel of the 9th U.S. Circuit Court of Appeals declined to order the state to segregate the ballots.

It is not yet clear whether the Supreme Court will take up the case or issue a decision before Election Day. California and Los Angeles County have argued that the federal list is unreliable and that creating a new system to separate ballots while voting is underway would be impractical.

In Friday’s ruling, 9th Circuit Judges Mark J. Bennett and Gabriel P. Sanchez warned that granting the DOJ’s request could lead to disenfranchisement and threaten the county’s entire election. They cited the Purcell principle, which generally cautions against changing election rules immediately before an election, along with the constitutional authority of states to conduct elections.

The judges also referred to the National Voter Registration Act, which prohibits states from systematically removing ineligible voters within 90 days of a federal election. Judge Patrick J. Bumatay, the panel’s third member, dissented.

The number of ballots actually affected is likely far below 20,000, because county officials found that many people on the DOJ’s list were not actively registered to vote and had not been sent ballots.

The Supreme Court appeal is the latest escalation in the Justice Department’s conflict with California election officials. In recent weeks, DOJ officials have warned local officials that they could face criminal prosecution if they refused to cooperate with federal demands to segregate ballots. Last week, the department issued grand jury subpoenas to employees at the Los Angeles County Registrar-Recorder’s Office.

Sources: NPR Politics.