This race is reminiscent of the Massachusetts Senate race in 2012.
^^^
Basically this. They like Brown/Kirk, it's just they like Warren/Duckworth more. And partisan voting. But it's not out of the realm of possibilities that Kirk could just barely survive.
Plus, the Massachusetts narrative is better than Alaska because you've got a personally inoffensive, ideologically moderate-to-conservative male Republican Senator upended by a personally inoffensive, progressive female Democrat (we can add "progressive crusader" if Duckworth runs that line) in a Democratic Presidential year in a heavily-D state.
Kirk is nowhere near as popular as Brown was, half the state has no clue who he is. Kirk has made little impression on the voters a better comparison would be to Hagan who was just as anonymous.