BECKY BOHRER JUNEAU, Alaska — Alaska’s bitterly fought U.S. Senate race took a tumultuous turn less than two weeks before Election Day, with allegations of partisan tricks to recruit a candidate with the same name as the Republican incumbent, investigations and an effort backed by President Donald Trump to delay certification if two-term Sen. Dan Sullivan loses.

Voters were left sifting through the fallout in a contest headlined by Sullivan and Democrat Mary Peltola , a former U.S. representative. The contest, one of several expected to determine which party gains control of the Senate, brought top Republican officials to Alaska to rally for Sullivan, including Trump, who placed particular focus on a third candidate in the race, retired teacher Dan J. Sullivan . Trump called him “fake” and ordered the Justice Department to sue to block certification, pending an investigation into potential voter confusion.

Peltola called the lawsuit “just flagrant, flagrant corruption.”It was dismissed Sunday by a federal judge, prompting a Justice Department appeal.

The candidacy of Dan J. Sullivan, who finished third in the August open primary with 2.5% of the vote and has done almost no campaigning, dominated attention in the final days of the race. The New York Times last week reported that Peltola’s campaign appeared to be involved in efforts to recruit him, breathing new life into suspicions long raised by the incumbent that Dan J. Sullivan was a “sham” candidate intended to confuse voters.

Peltola denied involvement in any such efforts: “I am not interested in tricking voters,” she told supporters.

Dan J. Sullivan, who lives in the small fishing village of Petersburg, previously denied any contact with Peltola’s campaign. He has not returned messages in recent days.

The Justice Department last week confirmed the existence of a criminal investigation, but Alaska U.S. Attorney Michael Heyman would not say what potential crimes authorities were looking into or the targets of their probe. Donors to Dan J. Sullivan’s campaign, many in his hometown, said FBI agents have asked if they felt deceived by the lesser-known Sullivan.

The ballot distinguishes the two as Dan S. Sullivan, Republican and incumbent, and Daniel J. Sullivan Jr. , with no party affiliation.

Dylan Wood, who attended a Peltola rally in Juneau last week, said he will always vote for the “most progressive-leaning candidate” in a race and said that’s Peltola.

He said he didn’t know the truth behind the claims surrounding Dan J. Sullivan but worries about government interference in the election.

“The ballot is clearly marked Dan Sullivan, incumbent. If you want to vote for him, you can,” Wood said.

John Delgado, an independent who leans Republican, said Sullivan has done a good job and seems to be a “pretty classy act.”He said he thought Peltola should bow out of the race.

“If I heard her say that it didn’t happen or ‘I didn’t know nothing about it,’ I would just at that point just think even less of her, because I believe she’d be lying,” he said.

Peltola finished first in the primary, with 49.5% of the vote, followed by the incumbent with 41.4%. The remaining vote was split among 14 other candidates.

The race has drawn a flood of outside cash and an endless barrage of ads. The campaigns of Sullivan and Peltola have each accused the other of spreading lies.

Sullivan’s opponents sought to cast him as a rubber stamp of Trump. He was alongside Trump in late September when the president said South Korea planned to invest about $54 billion in a mega-liquefied natural gas project in Alaska, though South Korean officials said they needed to assess the project’s commercial viability before committing.

The retired Marine emphasized his support of Trump’s signature package of tax breaks, social service cuts and immigration enforcement that passed last year. Sullivan also said he was running on a record that included support for the military. Vice President JD Vance traveled to Alaska to rally support for Sullivan.

Sullivan said Peltola was ineffective when she served in the House and that Trump’s efforts to expand oil and gas development in Alaska were at risk if Democrats regained control of the Senate. “Alaska is the firewall for freedom for the entire country,” he told supporters.

He characterized as temporary the war in Iran, which has been blamed for spikes in fuel prices felt acutely in remote Alaska communities that rely on diesel for heat and electricity. He said the “forever war is the Democrats’ war against Alaskan energy.”Peltola tried to turn Trump into a vulnerability for Sullivan during a televised debate , blaming the president’s war in Iran for high fuel prices and the deaths of service members.

She sought to distance herself from national Democrats, saying she would “stand up to anyone,” including members of her party, to further Alaska interests.

“Alaskans who know me know that I’m not liberal or radical,” she said, adding that she wants to work “for the best interest of Alaskans in as nonpartisan of a way as I possibly can.”

She, too, expressed support for additional drilling and said she would be willing to work with Trump to make that happen. She said she worked well with Sullivan as part of Alaska’s three-person congressional delegation and that suggestions otherwise were a “sad shame.”Alaska has long had an uneasy relationship with the federal government, which owns about 60% of the land within the state. The relationship has been especially fraught under Democratic presidential administrations that have sought to restrict logging, mining and the availability of areas for oil and gas leasing over environmental concerns.

Peltola, who is Yup’ik, highlighted her roots in the state as both sides pushed to present the candidates as authentic voices for Alaskans. Her campaign filled her social media with photos from travels around the state and emphasized issues such as affordability and combating corruption in Washington, D.C.

A winner in the race might not be known for some time. Alaska accepts ballots that are postmarked by Election Day for up to 15 days after the election from overseas voters. That makes Nov. 18 the deadline for final receipt of ballots and when tabulations under the state’s ranked-choice voting system will be done. Under Alaska’s system, rankings come into play if no candidate earns more than 50% of the first-choice votes.