What’s interesting here is that many who hate Trump would probably prefer Pence though in a lot of ways he’s far worse. What the most strident Trumpophobes sense is that while Pence is terrible, he’s terrible in a familiar way. Trump is scary in a metaphysical way because he represents something new.
It will likely take a couple of years to see just what that means, and how things will shake out. But those having panic attacks and having tantrums in public are terrified of the unknown.
This is like people who stay in terrible and/or abusive relationships because leaving represents an unknown future (as opposed to a miserable, but predictable one).