"Young adults who scored higher on right-wing authoritarianism had less gray matter volume in the dorsomedial prefrontal cortex, a region involved in social reasoning. Meanwhile, those who endorsed more extreme forms of left-wing authoritarianism showed reduced cortical thickness in the right anterior insula, a brain area tied to empathy and emotion regulation."

Not only is it tribalism, it's also individuals fundamental anatomy. This seems like a very challenging problem if the people you are hoping to convince are hardwired against your message.

https://www.psypost.org/authoritarian-attitudes-linked-to-al... (layperson's summary)

https://www.ibroneuroscience.org/article/S0306-4522(25)00304... (actual study)