The Dems don’t even remember why they hate Trump in the first place.

Originally, the vitriol was because Trump was allegedly an agent of Russia. This turned out to be a lie. Yet they continue to hate him anyway, because the TV tells them to.

This is the power of propaganda.

Here is the “Two Minutes of Hate” from the movie, 1984. This is Orwell’s depiction of how The Party’s subjects were brainwashed to hate the enemies of the State. They are encouraged to hysterically express their anguish and hatred towards the political opposition of The Party.
The Democrat base are far closer to this than they realize. This is what the MSM has turned them into.