Republican senator Dan Sullivan and Democrat Mary Peltola advance in Alaska Senate primary

Incumbent Dan S Sullivan, the US senator, advanced in Alaska’s nonpartisan primary race for his seat on Tuesday alongside Mary Peltola, a former Democratic congresswoman.

With the top four candidates moving forward from Alaska’s open primaries to the general election, the Associated Press reported that Sullivan and Peltola, had qualified for the November’s general election.

Another Dan Sullivan, a retired schoolteacher and US Forest Service employee who infuriated his namesake senator by running as a long-shot Republican candidate, was in a distant third place with 80% of the vote counted, although his qualification had yet to be confirmed.

After 80% of votes were counted, Peltola led the primary, on 48%, while Sullivan, the senator, had 42.8%.

The result tees up one of the marquee races of this year’s US midterm elections, which could determine whether Republicans or Democrats control the Senate for the final two years of Donald Trump’s presidency.

First elected in 2014, Sullivan easily won re-election in 2020, but this year faces what is expected to be a stiff challenge from Peltola. She is the first Alaska Native ever to serve in the US House of Representatives, and won a special election for the state’s at-large congressional district in 2022, then a full term later that year.

In 2024, Peltola lost her re-election bid to Republican Nick Begich III, but is nonetheless viewed as a top-tier Democratic recruit to take on Sullivan in the Senate race. Both candidates are champions of Alaska’s oil and gas industry – a major employer and economic driver – but Peltola has sought to distinguish herself through her advocacy for the state’s fisheries and opposition to Trump’s economic policies.

Sullivan has meanwhile described himself as a reliable advocate both for the state’s oil needs and its military installations, while championing more popular aspects of the president’s agenda such as the tax cut extensions included in last year’s One Big Beautiful Bill Act.

But Sullivan’s path to retaining his seat in the US Senate has been complicated by the emergence of Dan J Sullivan, his namesake rival, who is also running as a Republican. Alaska Republicans have condemned him as a “sham” candidate who is backed by Democrats and running solely to confuse voters, but their efforts to disqualify him from the race were unsuccessful.

Alaska figures prominently in Democrats’ ambitious plans to retake the US Senate, which would require flipping at least three Republican-held seats in states that voted for Trump in 2024. The party is hoping to see its candidates elected in North Carolina, Maine, Ohio and elsewhere, but is also defending seats in Georgia, Michigan and New Hampshire.

Peltola, who Politico reported recently replaced her campaign manager, has raised more than $18.5m this election cycle, with upwards of $4.6m on hand. Sullivan has brought in more than $11.7m, with nearly $7.3m on hand.

In the primary for Alaska’s sole US House district, Begich advanced to the general, alongside his main challenger, independent Bill Hill.

Alaskans in November will also elect a successor to incumbent Republican governor Mike Dunleavy, who is barred by term limits from seeking re-election. In a crowded field of 17 candidates, Democrats Jonathan Kreiss-Tomkins and Tom Begich advanced to the November election. Two more nominations remain open, with 80% of votes counted.