The Justice Department asks a judge to set Alaska's Dan J. Sullivan ballots apart, and confirms a criminal investigation into the second Sullivan on the ballot

Four days before Alaskans vote, their Senate race is in a federal courtroom. On Friday the Justice Department asked United States District Judge Sharon Gleason to order state election officials, before Monday, to preserve and segregate all ballots ranking Daniel J. Sullivan, so investigators can test later whether those rankings came from voter confusion. Associate Attorney General Stanley Woodward wrote that the measures are modest and precautionary, and that they will be impossible after Election Day, which is why the court should act fast.

The filing is one piece of a much larger move. United States Attorney Michael Heyman, the top federal prosecutor in Alaska, confirmed on Friday that a criminal investigation into the second Sullivan's candidacy has been under way for months. He would not say what crimes investigators are examining or who their targets are. The department has issued at least three dozen new subpoenas and document preservation requests since Thursday, including subpoenas to the campaign offices of Mary Peltola, the Democratic nominee, and of Daniel J. Sullivan himself. Three further filings on Friday sought expedited answers from Peltola's campaign and from the Democratic Senatorial Campaign Committee about their reported role in recruiting him. The civil side of the case, which President Trump has said he ordered, asks the court to bar Alaska from certifying the Senate result if Senator Dan S. Sullivan loses by a margin that confusion between the two names could explain.

The reporting that forced the issue came from the New York Times on October 28. The Times, working from text messages, interviews with 12 people and documents prepared for a possible lawsuit, reported that people tied to Peltola's campaign and to the Democratic Senatorial Campaign Committee spent months on what they called a ballot composition project, recruiting the retired teacher Daniel J. Sullivan Jr. and other spoiler candidates to shape the four candidate general election ballot. Alaska uses ranked choice voting, which makes a namesake candidacy more potent, not less: a voter who ranks the wrong Sullivan first has still cast a countable vote for him.

Everyone accused says the accusation is wrong. Peltola told supporters in Juneau on Thursday that she knew nothing about any other candidates on the ballot except herself and the incumbent. Her campaign and the Democratic Senatorial Campaign Committee have denied coordinating with the second Sullivan, and Daniel J. Sullivan has said since June, and again this week, that he had zero contact with Peltola's operation and entered the race on his own. No charges have been filed against anyone. Alaska's own courts ruled earlier this year that a motive to confuse voters is not, by itself, a legal reason to strike a candidate from the ballot, and the state supreme court let him stay on it in June. Governor Mike Dunleavy ordered a separate state investigation on Thursday.

Trump has said repeatedly that the second Sullivan should be removed from the ballot, and he said on Friday morning that he does not know whether Senator Sullivan can win with the ballot as it stands. House Oversight Chairman James Comer has asked Peltola's former campaign manager Elisa Rios and operative Jerid Kurtz to sit for voluntary interviews on November 5 and 6.

What the court decides by Monday will not remove anyone from the ballot. It will decide whether the ballots that rank the teacher are kept apart from the rest, in case a court later has to judge what confusion did to a Senate race that could help decide which party controls the chamber. The investigation will still be running on election night either way.