This is one of those unique situations where, yes, it's bad that Delta would take a customer out of their pre assigned seat (whatever the reason) but:
1) She previously applauded Uniteds treatment of the doctor, called him a drug addict and called for his deportation
2) Spews vile hate speech and racism
3) Reacted to this in a extremely inappropriate manner by going on her little rant.
Those reasons make me have 0 sympathy for her. Sure....having your seat taken isn't something that should happen to anyone, but there are some people who are just such a disgusting excuse for a human being that it's impossible for me to have ANY sympathy for her.