When people sense the bully is about to get his due ...
Back in school I noticed there was a certain kind of weak individual who would run around in the school bully's orbit and show deference to him ... until someone stood up to the bully and gave him a taste of his own medicine. Then you'd see that person cheering on the person who beat up the bully.
I think there are some people like that among those who claim to be "undecided" at this late date. Appealing to people like that is why it's been important for Trump to portray strength in the upcoming election and to generate momentum, such as through the Hunter smears.
But it doesn't seem to be working. The polls have been very good this week, and the recriminations have already started to filter out of the Trump camp. I'm hopeful that this means that Biden will be able to ad an extra percentage point or so to his total, from those people who just gravitate to the winner. They are sad people, but their vote counts just as much as anyone's, and they help explain how landslides unexpectedly happen.