Humans lived in tribes for millions of years. Tribalism is hard-coded into our brains.
An attack on the tribe is considered an attack on every individual within the tribe. Saying "Trump is racist" is an attack on everyone in the MAGA tribe and makes you an enemy of the tribe. Not someone to be trusted. Someone to fight back against.
Things that are obvious to anyone outside of the tribe won't even be considered by anyone within the tribe. If there's any doubt, the other members of the tribe will tell them "no, we aren't racist, they are the racists!" The obvious thing becomes a lie and rejected.
Even when something impacts your life, you may think "well that was just a mistake" so you can continue feeling happy to be in the "good tribe".
No one is good at questioning these things because we don't want to think of ourselves as not all that much more evolved than apes. So we develop ideologies to paint over how we really think.
Are you able to question your tribe? What are the things that are obvious to anyone not in your tribe that you can't consider?
Whose faces do the leopards you hang out with want to eat?