From what I've seen, one of the more common "blue tribe" beliefs these days is that there are in fact two sides - either you're a good person who holds all of the correct beliefs that every decent person has, or you're the enemy. A few months ago, a whole bunch of the social justice-y folks on Mastodon actually turned on its creator in #ForkOff because he introduced a popular tags feature that (in their eyes) every good-thinking person should realise was a bad idea, and therefore was a bad person and should be shunned. (Not sure how tightly-policed the red tribe is these days.)
It's called "outgroup homogeneity," when you are part of an us-vs-them scenario your "us" always seems to be a coalition of diverse viewpoints whereas your "them" is a single collective viewpoint.
So for example if you are in a team of white males you might want to get a token black person or a token woman on your team to "bring the black perspective" or "bring the female perspective" to whatever you're working on: that's a systematic bias, you're implicitly assuming that there's not going to be a diversity of black/female perspectives the way that you already know there's a lot of white male perspectives.
In fact the broader issue that will lead the US inexorably to civil war even if present communications difficulties abate is that we do elections by dividing our electoral bodies into independent seats and then run first-past-the-post elections for each seat. The issue is fixed-point theorems. Each election is a polity -> polity map; the fixed point of split-FPTP-elections is a polity which is 50% one party, 50% the other party, both parties are completely spineless chameleons which shift however they need to in order to maintain the 50/50 status quo, and people are loosely affiliated with one party while disgusted by the opposition. As the first US civil war showed, this disgust will naturally build without bound until the highly prominent issues at the time cause movements toward secession which then lead to active conflict.
I was going to say "if you're coming from a place that does proportional elections this probably seems like nonsense to you," but that is my own outgroup homogeneity effect rearing its ugly head again! The truth is that even proportionate systems have problems with this sort of divisiveness; witness Brexit in the UK and Geert Wilders in the Netherlands for two examples. But I would insist that there is a characteristic spinelessness that pushes this further from just "we are one nation with serious divisions to reconcile" to "they are awful and we will never reconcile, let's just get a divorce" in the US system.
Wilders funding [1] suggests that US conservative money (previously under the guise of anonymity) is manipulating the Dutch electorate perhaps in a similar way as some wealthy Russians manipulated the US electorate.
I don't really know what these red/blue tribes represent, but the way you describe "social justice-y folks" seems to coincide with the way Jordan Peterson and Sargon of Akkad criticise third-wave feminism for being marxist and controlling. Ironically marxists are traditionally identified by the color red.
Unfortunately, authoritarianism and the desire for thought control is never tied to one political ideology. It will always seem like an option to those in control.
I don't know if the Japanese softcore child porn wave seems to be a symptom of people being unable to find a safe middle, or if it's a late consequence of cultural globalism. Lacking an over-all perspectives in a foreign culture makes this kind of analysis hard.
Unfortunately, authoritarianism and the desire for thought control is never tied to one political ideology. It will always seem like an option to those in control.
Obviously the latter statement is true, everything will seem like an option, but the sentiment you're getting at here doesn't seem to be true.
The US Congress could have repealed the first amendment at any point since it was introduced. They never have. And the US, for all its problems, has significantly freer speech than most of the world. America is also a notoriously conservative sort of place.
Places with alternative political ideologies very rapidly encounter authoritarianism and thought control. See: China.
