The Supreme Court on Monday turned away a final federal attempt to make California hold back thousands of mail ballots, clearing the way for the state to count them as usual just hours before polls open for the midterm elections.

The Justice Department had asked the justices to order California election officials to keep apart the ballots of roughly 20,000 voters the government says are likely not U.S. citizens. The court denied the emergency request in a single sentence released shortly before 5 p.m. Central. The order was unsigned and no justice noted a dissent.

The justices did not even ask California to file a reply before ruling. The request first went to Justice Elena Kagan, who handles emergency appeals from the West Coast circuit. She sent it on to the full court.

What the government wanted

Solicitor General D. John Sauer filed the request Monday morning. He argued that once the challenged ballots are mixed in with everyone else's they can never be pulled back out. He also pointed out that California accepts mail ballots that arrive up to a week after Election Day, so the harm the government claims would keep growing through Nov. 10.

Federal officials first told the state and Los Angeles County about the list in October. Since then they have sent letters to all 58 California counties naming voters they want flagged. The state has more than 23 million registered voters.

A week of losses in court

Monday's order was the fourth time in about a week that a court rejected the push. An appeals court threw out the government's first appeal on Oct. 26 because it had rushed past the trial judge. Two days later U.S. District Judge David Carter refused to order the ballots set aside, writing that the method used to build the list was full of uncertainty and mistakes. A divided appeals panel then declined to step in on Oct. 30.

State officials have said that when they checked a sample of the names a large share turned out to be citizens. The government has not explained how it put the list together. Reviews over many years have found that noncitizen voting in federal elections is very rare.

California reacts

Attorney General Rob Bonta said the string of rulings should end the effort to disrupt the state's election through emergency court orders, though he promised to stay on guard. Gov. Gavin Newsom said the courts had done their job and urged anyone who has not voted to drop off a ballot.

Secretary of State Shirley N. Weber, the first Black person to hold that office in California, said the fight is not over but that voters can now focus on what matters most: casting a ballot.

Once the disputed ballots are opened and processed they cannot be traced back to individual voters. That means the ruling all but ends any chance of separating them for later review.

Election Day is Tuesday, Nov. 3. California voters can still return mail ballots at drop boxes and polling places through 8 p.m. Pacific time.