The Forecasting MachineOpen interactive report

Which party will win the 2026 US Senate election in Alaska?

The election will determine the representation for Alaska in the United States Senate, with incumbent Republican Dan S. Sullivan facing Democratic challenger Mary Peltola, among other candidates. Alaska's use of ranked-choice voting may influence the outcome.

Forecasted on

Forecast probabilities

  • Democratic Party: 61.1%
  • Republican Party: 38.1%
  • Other / Independent: 0.8%

Reasoning

Mary Peltola is the favorite, but not by enough to make this anything other than a close race: the forecast is Democratic Party 61.1%, Republican Party 38.1%, and Other / Independent 0.8%. Her polling advantage and a favorable national environment outweigh Alaska’s Republican lean, while turnout, ranked-choice transfers, and the late campaign controversy leave Dan Sullivan with a substantial path to victory.

Democratic Party — 61.1%: A narrow polling edge meets a strong national tide

Peltola’s strongest case is the consistency of the evidence pointing her way. She led Sullivan in the August primary, and Alaska Survey Research’s ranked-choice simulations repeatedly gave her a small final-round advantage; the latest New York Times/Siena poll also found Democrats ahead in Alaska, though within the margin of error [a3, a5, a6, a8] [e1340, e1317, e1318]. That fresh result matters especially because an earlier Siena poll had Sullivan ahead on first choices: the late poll suggests the contest has moved, even if it does not settle it [a7] [e1319].

The national setting adds weight to that signal. Trump’s approval has fallen, Democrats have opened a substantial generic-ballot lead, and a late round of race-rating changes overwhelmingly favored them [e1169, e1173] [e1358, e1359]. Peltola has also shown she can compete statewide in Alaska’s ranked-choice system: she won a House seat in 2022 and came close again in 2024 [a5, a6]. The latest poll and the national climate make her the more likely winner, but the narrowness of her polling lead argues against treating her as a strong favorite.

Republican Party — 38.1%: Alaska’s partisan baseline and turnout remain powerful

Sullivan’s best argument is the state itself. Alaska has voted strongly Republican in recent presidential elections, and Republican-leaning voters outnumber Democratic-leaning voters [a6, a7, a12]. Sullivan also has incumbency, while the three-Republican, one-Democrat ballot could help him if lower-ranked Republican preferences consolidate behind him [a10]. That mechanism is plausible, but it has not been enough to erase Peltola’s lead in the available ranked-choice polling.

Turnout is another genuine risk for the Democrat. In 2024, Peltola led the primary but lost the general election as a more Republican-leaning electorate turned out [a5]. The effect may be smaller in a midterm than in a presidential election, but it is a reminder that primary results and polling snapshots do not determine who actually votes.

The final-week dispute over the second Dan Sullivan adds uncertainty in both directions. Reporting alleged that operatives connected to a pro-Peltola group recruited the candidate; Peltola denied knowing about the effort, while the allegations prompted investigations and drew public criticism [e1322, e1323] [e1324, e1332, e1341]. The story could mobilize Republicans or damage Peltola with some voters, though it does not establish her involvement. A federal judge dismissed the Justice Department’s attempt to block certification under specified conditions, and the administration appealed; that creates some procedural uncertainty, but is not itself evidence that Sullivan is more likely to win the vote [e1312, e1315].

Other / Independent — 0.8%: A remote possibility

The ballot includes candidates besides the two major-party nominees, and the second Dan Sullivan has attracted attention because of his similar name and the controversy surrounding his candidacy [a10] [e1330, e1341]. But the central contest remains between Peltola and incumbent Dan S. Sullivan, and ranked-choice transfers make an outright win by a minor-party or independent candidate unlikely [e1310]. The forecast therefore assigns this outcome only a small residual chance.

Why the balance favors Peltola, but only modestly

The evidence is not all pointing in one direction: Alaska’s partisan lean, Sullivan’s incumbency, potential Republican vote consolidation, and turnout patterns make a Republican win quite plausible. But repeated ranked-choice polling advantages for Peltola, a late poll that again puts Democrats ahead, and a strong national environment collectively tip the balance toward her. That combination supports a 61.1% Democratic chance against 38.1% for the Republican, with 0.8% for Other / Independent: a real but limited edge for Peltola, not a prediction of an easy win.

Update summary

A new late New York Times/Siena poll puts Democrats ahead in Alaska, adding support for Peltola while leaving the contest close [e1317, e1318]. A judge dismissed the DOJ’s bid to block certification, but the administration appealed, so the ruling changes the procedural outlook more than the expected vote outcome [e1312].

Cited evidence