Alaska definitely needs investment, and it frankly wouldn't take all that much to reach maximum saturation in terms of effect.
Worth noting: Alaska is the only swing to swing Democratic in the past three elections.
2000: Bush +30.95
2004: Bush +25.55
2008: McCain +21.53
2012: Romney +13.99
Something is definitely going on. You're already at the point where Democrats can play in Senatorial elections; the fact that Begich won in the first place - and then lost by only 2 points in a midterm wave - should be all the justification in the world needed for consistent infrastructure to be put into place.
He was the perfect fit for an Alaska Democrat with a very, very strong campaign, while Sullivan is your generic R. He won in the first place after the incumbent was indicted. Not exactly typical scenarios.
I would wait to see another election to see if it could be in play. I do think it is Likely R for a reason though.