Here's my theory.
Many of these people didn't want Hillary because they were butthurt over the primary, but they REALLY REALLY didn't want Trump. Deep down they knew they didn't want Trump but deep down they thought he had no real chance of getting elected.
NYT's and Huffington Post had Hillary winning at a 99% chance.
When you know that the "lesser" of two evils, at least in your eyes, is indeed going to win, you don't feel any guilt about protesting, bashing, dragging, etc. You get to feel self-righteous and pure without any guilty feelings. Sure, people warned you, but you dismiss them because you know that your vote doesn't REALLY make the difference.
Then, election night comes and you realize what you've done. Deep down, in the back of your mind, you realize what you are guilty of. Those people who voted to make themselves feel pure rather than to protect their country... they now have to deal with what happened and their cognitive dissonance is too painful for them to admit that it was there fault.
Deep down, they know they are wrong. They know what they did was wrong. They know, in their heart of hearts, that it was wrong not to vote for Hillary and a part of them will probably never forgive themselves, but now it is too late. The damage is done. Their only way to escape the cognitive dissonance of realizing everything they thought they knew was wrong is to continue to deny it. Double down. Lie to themselves until they convince themselves that what they did was okay.
Maybe, instead of hating them, we should show more sympathy toward them.
They made an awful, awful mistake and now they are having to deal with it in their own way.