> what happens when you self-identify with a party rather than principles and put your intellect to work rationalizing positions selected by other people

This is a problem for a lot of people, regardless of political spectrum.

When your identity is tied to a political group, criticism of that group transfers to criticism of self, and there aren't many people that enjoy that.

That has certainly been the case for the past few decades and I, personally, think we may have reached some sort of breaking point. The other day on a somewhat popular radio show catering to a specific group typically associated with one US party the calls to divest from political affiliation to a Party as a deciding factor were a lot more common and urgent in tone. I know what I think and I do think US 2 party system is part of its current set off issues, but it was odd to hear some of those thoughts expressed in the wild.

Don't get me wrong, the tribe mentality is absolutely still there, but for the first time in a while I am hearing something akin to 'fuck it'.

Yes - it’s a cognitive pitfall humans are prone to. You can see it with any group membership - here on HN, how many comments have we seen where someone is defensive about legitimate criticism about their favorite programming language or style – but it can be especially bad with politics because it can be weaponized by people acting in bad faith with significantly more negative consequences.