Everyone wants to hate something, and they want to feel superior to someone else. If you can give that to them, you can get them to do ANYTHING you want. Good or bad.
The Left (especially, but not exclusively) hates Trump because of what he represents, not just because of what he is. He's a very easy target to hate, because he represents many of the few remaining things that you're actively allowed to hate on in America without being cancelled: he's white, male, hetero, perceived as Christian (although think he said he isn't?), rich, on the political right, and oh yeah, a proud American. That's a pretty good summary of the only things you're allowed to hate in America in 2024, anything else and you're some flavor of -ist or -ism.