For nonexecutive positions - Congress, State Reps - the general idea that you should "vote on character" or similar nonsense is, well, nonsense. Sure you don't want somebody there to steal the farm, but even then mostly because you don't want them embarrassing the party generally. Even for executive positions - governor, president - it's much less nonsense, but still not the important thing most of our political coverage emphasizes. Just how gross would a Democrat have to be for any of you to pull the lever for a Republican governor? President?
Putting perhaps the most corrupt human being, something only in doubt because of his lack of brains and imagination, ever to be born into this world in charge of the country is not ideal, but I'm not completely surprised that focusing on his obvious character flaws is less of a clearly winning electoral strategy than people would hope.
And true swing voters, the people who vote fairly regularly and really do switch back and forth between parties, are...kinda weird and uninformed, generally. They're hard to reach because they aren't the idealized Centrist Man, but a mess of idiosyncrasies and misunderstandings.