A New York Times/Siena College poll suggests the future of the Senate majority might be in part decided by a race in Nebraska—one that’s nearly tied because of the unexpected popularity of an independent candidate named Dan Osborn.

Democrats have controlled the Senate since winning key elections in Georgia that gave them a slim majority in 2021. Republicans took back the House in the 2022 midterms, and Democrats extended their narrow Senate majority to 51-49. Democrats face tough odds to keep control of the Senate, having to defend seats this year in the critical battleground states of Pennsylvania, Michigan, Wisconsin, Nevada and Arizona, along with the heavily Republican-leaning states of Montana, West Virginia and Ohio. Osborn’s sudden popularity represents an unexpected obstacle to Republicans' chances, though. His election would replace a Republican seat with an independent who could play a wild card role in each decision, with the potential to vote for or against any coalition that formed, as Osborn has said he will not caucus with either party. Republicans have an 88% chance of gaining control of the Senate, according to a FiveThirtyEight analysis, while their odds are much slimmer—53%—of retaining control of the House of Representatives.

Osborn’s claim to fame comes from a monthslong strike of more than 1,000 workers in his local union at a Kellogg cereal plant in an employment dispute. Osborn was president of the Omaha-based union and led the 2021 strike. Today, he works on machinery and piping systems as part of a steamfitters union. He also has served in the Nebraska Army National Guard and the U.S. Navy. As an independent, Osborn’s platform touches both sides of the partisan spectrum. His campaign, often described as populist, advocates for tax cuts for small businesses and the middle class. His website states that he “does not support extreme national measures to ban abortion” and that he is a self-described supporter of the Second Amendment interested in limiting what he calls governmental overreach. He also states that he wants to prevent illegal immigration and strengthen border security, one of former President Donald Trump’s most-known and supported points. In interviews, he regularly airs grievances with the two-party system. “I need to navigate down the middle because that's what … the two-party doom loop means," Osborn told ABC News in October. He has refused to state whether he will vote for Vice President Kamala Harris or Trump in the coming election, The Wall Street Journal reports. Fischer and Trump have both likened Osborn to a Democrat.

Fischer in 2012 became the first female Senator elected for a full term in Nebraska, beating her Democratic challenger by more than 15 points. She won reelection in 2018 in a more than 18-point victory. She has voted to repeal the Affordable Care Act and sponsored bills to enact strict abortion bans. She also is a cattle rancher and has served in the Nebraska legislature. While she called for Trump to step aside as GOP presidential nominee in 2016, she later voted for his acquittal in both of his impeachment trials and has endorsed Trump’s campaigns. Trump endorsed Fischer on Sept. 9, saying in a post on Truth Social she has “done a fantastic job.” In the same post, Trump called Osborn a “Radical Left” candidate and a “Bernie Sanders Democrat.”

FiveThirtyEight shows Fischer (45.5%) leads Osborn (44.5%) by one point, making it one of the tightest Senate races. In September, Cook Political Report restated its outlook on the Senate race, saying Nebraska may “lean Republican” rather than is “likely” Republican.