"Everyone knows" the politicians are a bunch of smarmy crooks and all they give you is sound bites of general ideas, with no specifics, during the campaigns. That makes it hard to even find differences, except perceptions of attitude, but even those are usually of the party and not the candidate.
Because of the sameness, a lot of voters will seize of a single point like abortion, gun control, crime rates, etc, and vote for the one that they think agrees with their position on that issue.
Of course the perception may be wrong on that issue plus big surprises on things they haven't even considered. But, they'll keep backing their choice rather than admit making a mistake, saying the other guy would have been worse.
One of the reasons I hated Nixon with a zeal akin to TW's regard for Bush, is that I voted for him the first time and be betrayed me.
