To the extent that membership in a political tribe is premised not on policy issues but on the acceptance of shared heroes and narratives, political tribalism requires a certain abdication of critical thought and an indifference to history. The difficulties this creates for self-criticism and self-correction are obvious, but one of the reasons why political tribes insist on maintaining their myths is the same reason why any group does this, which is to give their allegiances greater meaning than they would otherwise possess. Another reason why political myths are so powerful and enduring is that they help to justify past actions that cannot really be justified and to cover over present actions that need to be forgotten.
In the past, I have been characterized as some kind of a wacko because I look down on political animals, those people whose entire lives revolve around their imaginary power to influence the course of events by pretending that their minds are perfectly in tune with some important person or political party. For some reason, “freethinking” atheists and “individual-rights” conservatives are particularly susceptible to the absurd belief that by identifying with some arbitrary crowd of mindless sheep and revering some arbitrary symbols of mindless conformity, they will attain ultimate cosmic power and give meaning to their empty lives.
It’s OK to think about political questions and consider political methods, but when someone makes party politics central to their psychology, they have really just given up on reason and admitted that they want someone else to tell them what to do. In another culture, they would be marching up to the altar to sacrifice themselves or their child to the ravenous pagan gods; or they would be gleefully watching their neighbor get beaten by the secret police for reading a Bible; or they would be in the crowd shouting for someone to be burned, lynched, crucified, or guillotined.