Alaska’s closely watched U.S. Senate race has taken an unusual turn: two candidates with nearly identical names are on the ballot. Republican incumbent Dan S. Sullivan is running against Democrat Mary Peltola, while another candidate, Daniel J. Sullivan Jr., is also in the race. The ballot lists the challenger as unaffiliated.

The second Sullivan’s candidacy has been disputed for months. Alaska election officials initially tried to keep him off the ballot, saying his filing raised concerns that voters might confuse him with the incumbent. He appealed, and Alaska’s courts ruled he could remain on the ballot. The courts did not determine whether he intended to mislead voters.

The controversy intensified this week after The New York Times reported that Democratic operatives with ties to Peltola’s campaign helped recruit Daniel J. Sullivan to run. The report cited text messages, interviews and documents. Peltola’s campaign and the Democratic Senatorial Campaign Committee have denied involvement in recruiting him. The report has prompted Alaska Gov. Mike Dunleavy to order a state investigation, while the U.S. Justice Department has escalated its own inquiry with new grand jury subpoenas.

Republicans say the similar names could confuse voters and split support for the incumbent. President Donald Trump has accused Peltola and Democrats of election fraud and called for prosecution. Those are allegations; the reporting has not established that laws were broken. The challenger has denied that he is trying to mislead voters.

The Justice Department has also sued Alaska, seeking to prevent certification of the Senate results if the incumbent loses by a margin that could have been affected by voter confusion. Peltola’s campaign is asking a judge to dismiss the lawsuit, arguing that election administration is a state responsibility. The case adds another legal fight just days before the November 3 election.

Alaska’s ranked-choice voting system lets voters rank candidates in order of preference, which could lessen the effect of votes cast for the wrong Sullivan. Still, the dispute has put ballot clarity, campaign tactics and control of elections under a national spotlight—with the outcome of a competitive Senate race at stake.