ANCHORAGE—As winter set in and Election Day neared in Alaska, high prices for diesel and home heating oil drove voter anger at President Trump and incumbent Republican Sen. Dan S. Sullivan, making the Senate race in this red state one of the most competitive in the country.

Now, with just days to go, allegations that Democrat Mary Peltola’s campaign secretly worked to recruit a spoiler candidate to help her party win the pivotal Alaska seat—and potentially retake control of the Senate—has become this midterm election’s biggest October surprise.

For months, Republicans raged over the presence on the ballot of a retired teacher named Dan J. Sullivan Jr., who is one of four finalists for the Senate seat held by Dan S. Sullivan, potentially confusing voters. President Trump directed the Justice Department last week to sue Alaska, seeking to delay the results if the incumbent narrowly loses.

Then the New York Times reported on Wednesday that staffers with Peltola’s campaign had worked with people to recruit the other Sullivan as a spoiler in the race—a strategy that her campaign had long denied. The state’s governor, Mike Dunleavy, a Republican, ordered an investigation as Trump amped up his attacks, calling for Peltola and the other Sullivan to be criminally prosecuted and tossed off the ballot.

The Justice Department on Thursday expanded its criminal investigation, sending dozens of new grand jury subpoenas, people familiar with the matter said.

“Never a dull moment in the great state of Alaska,” Sen. Sullivan said in an interview Thursday. “I think Alaskans, the more they understand this, the more they’re going to be repelled,” he said, predicting he would get Democratic votes out of it. Dan J. Sullivan Jr. couldn’t be reached for comment.

America’s Last Frontier already was a chaotic Senate battleground. Alaska is seen by both Republicans and Democrats as one of a handful of states needed to win control of the chamber. Candidates and outside groups have poured more than $130 million into the race, shattering records, in a state with only about 740,000 residents.

Polls show a tight contest. Sullivan hasn’t distanced himself from the president on tariffs or the Iran war, as some vulnerable Republicans have done. Instead, he is running as a close Trump ally, making the case that he can do more for Alaska by nurturing goodwill and relationships inside the administration. He rallied with Trump in the Republican stronghold of Wasilla earlier this month, hoping to boost GOP turnout.

As the recruiting controversy rocketed onto cable TV and social media, Peltola has tried to brush it off and stay focused on her closing message, which links surging fuel prices to Sullivan’s votes in the Senate against ending the Iran war. At a campaign event on Wednesday, she called the Times story “nonsense” and said the race is about big issues like affordability in Alaska. “This is just another distraction,” she said.

Whether voters agree could determine whether Alaska stays in the Republican column or flips blue.

Kati Capozzi, 44 years old, president and CEO of the Alaska Chamber of Commerce, voted early for the GOP senator. About 41,000 Alaskans have already voted, and more than 16,000 have returned mail-in ballots. She said Alaskans have been educated about the two Sullivans for months, so voter confusion isn’t a huge problem. “We kinda got over it.”The bigger point, Capozzi said, is that Democrats tried to fool voters, and that could affect how some Alaskans think about Peltola.

She pointed to a statement from Alaska Sen. Lisa Murkowski—a Republican who endorsed Peltola in her 2022 and 2024 House races but has backed Sullivan for Senate—who said the Democratic candidate owed Alaskans answers.

“I think people are starting to realize that Mary is maybe not the person that they thought she was,” Capozzi said. Sullivan will need some Murkowski voters to win, she said, “and there’s a lot of people who look to Lisa for guidance.”Like most Alaska voters, Melissa Chaney is unaffiliated with any party. The 62-year-old retired high-school counselor in Anchorage said she has voted for Murkowski in the past, and now she supports Peltola. She said she doesn’t think the New York Times reporting will have any impact.

“I can’t say there weren’t any shenanigans, but what I can tell you is that we are used to people pulling shenanigans,” Chaney said. “If the Republicans could have found another Mary Peltola to put on the ballot, they would have done that.”The Alaska Supreme Court has ruled both Sullivans can appear on the ballot. The current senator’s party affiliation and incumbent status are listed next to his name. Recruiting long-shot candidates to siphon votes away from contenders, sometimes called ballot stacking, isn’t usually illegal, unless the tactics are combined with some other violation, like lying to a court.

Adding to the drama is Alaska’s ranked-choice voting system: Voters rank the four finalists on their ballots in order of preference, and if no one gets more than 50% of the vote, the weakest candidate is eliminated and the second-choice votes on those ballots are redistributed to remaining candidates. The process continues until someone has a majority. But the ranked-choice tally won’t happen before Nov. 18, the deadline for absentee ballots, so the winner—and which party controls the Senate—might not be known for weeks.

Independent voter Mark Hayward, 58, of Nome, said he ranked Peltola first for Senate, but for his fourth and last choice he wrote in “a Dead Moose” so that he didn’t have to rank the incumbent senator. He is furious with Sullivan, who he said “has become an important enabler of this president.”Hayward said most voters in Alaska are more concerned about fuel costs and fish conservation than ballot-stacking efforts by either party.

“What matters in Alaska is gas prices. Fish is a close second,” he said.

Peltola, 53, who previously served in the U.S. House, would become the first Alaska Native in the Senate if she wins. In the final days of her campaign, she homed in on fuel prices, drawing applause from Alaska Native leaders gathered for an annual convention in downtown Anchorage when she said Alaskans should not have to choose between heating their homes and feeding their families.

The pain is particularly acute in rural areas, where residents rely on diesel for electricity generation and heating oil to warm their homes. Diesel is 60% more expensive than a year ago in Alaska.

“We’re just getting crushed,” Peltola said in an interview last week. “It does feel existential.”Sullivan, a retired Marine and former state attorney general, was first elected to the Senate in 2014, unseating a member of a famous Alaska political family, Democratic Sen. Mark Begich. Back then, he was the one known as the “other Dan Sullivan”—to distinguish him from the former mayor of Anchorage, who also happened to be named Dan Sullivan.

Sullivan, 61, has built a reputation among supporters and colleagues as a workhorse for his state, pushing relentlessly for oil and gas development and to deliver more federal resources, from a fleet of new Coast Guard ice breakers to funding for high-speed internet in rural Alaska.

In a speech at the Native convention, Sullivan expressed concern about high fuel costs, and said the Trump administration had created an energy task force focused on bringing down prices in rural Alaska, including by doubling heating assistance for low-income families and investing to upgrade the grid.

But he didn’t mention the war. Sullivan voted 14 times against Democratic-led resolutions that would have forced Trump to withdraw troops from hostilities against Iran, a number that features prominently in Democratic ads here.

Sullivan said he is no rubber stamp for Trump, citing behind-the-scenes efforts to help persuade the administration not to livestream an execution of convicted shooter Maj. Nidal Malik Hasan.

“To me, the north star is how do you effectively get what you want for your constituents? And I think I’ve been enormously effective on things that matter to our state,” he said.

Bill Armstrong, the owner of Armstrong Oil & Gas, has been friends with the senator for about 25 years. He said he has a hard time believing some recent polls, which show Peltola with a slight edge in a state Trump won three times by double digits.

“I think Trump has been a really good president for the state of Alaska,” Armstrong said, “but when you just listen to the constant drumbeat of negativity towards Trump, I think a lot of that rubs off on Dan.”Innokenty Lestenkoff, a 55-year-old Republican maintenance worker, voted early for the senator and doesn’t think high prices are Trump’s fault, much less Sullivan’s. “I’m sure it’s just until the war is over and then it will drop back,” he said.

For rural Alaskans, many of them Alaska Natives, a hard winter is ahead. Data is hard to quantify at this point, but rural household utility costs could be $1,000 to $2,000 higher this winter because of the war, according to Brett Watson, associate professor of applied and natural resource economics at the University of Alaska, Anchorage.