USPG2 and the TDS threads are just a microcosm and reflection of the current political climate. Both homogenized by peer evaluation with immediate mistrust of and hyper vigilance against incongruity. Ideology becomes so distilled and guarded, mixing them is like oil and water.
Its happening irl too.
You're missing the forest for the trees. The conflict isn't political but you're correct in that they two sides cannot mix.
What you're witnessing isn't a polarization of political camps. It's a debate, a final war over the definition of morality. A war that's been ongoing longer than you or I have been alive. The fundamental disagreement of the Left and the Right is the origin of morals and foundation of law. The right believes that law is downstream from morals and that morals are objective not subject. The left is the opposite, they believe that morals are subjective and thus so is law. Let me give you some examples.
•to murder is wrong
-The right believes this is true in all cases, because murder is wrong according to objective morality. Killing someone and murdering someone are defined differently but murder is never justified.
-the Left doesn't believe murder is inherently wrong on principle. Some murders to them are justified because in their morals are subjective and in their eyes murdering someone is justified if they meet certain criteria. They completely ignore your objective right to not be harmed if you aren't harming them.
•Stealing from others is wrong
-the right believes that you should not take what isn't yours. objective morality tells you that stealing is wrong on premise even if you're starving or in need. It's better to ask for help than to steal.
-the Left believes that stealing in some scenarios is justified because they don't believe in objective morality. Subjectively if you are in need then you do what you need to survive because that benefits you. If others are wronged that's irrelevant because they have more than you and thus deserve to be stolen from.
Like it or not the western world created it's laws in line with certain theologies. Meaning they were written assuming that morals were handed down by a higher power. Good and evil were assumed to be objective and not subjective. And this is the fundamental disagreement between the left and the right. The right believes that they cannot murder you for any reason because it's wrong. They can kill you if you threaten their lives but that's it. The left believes that they can define morality and if you disagree killing you is justified because they don't believe in objective right or wrong. The left believes in no higher power than themselves and operate as such. The right, theist or not, believe that morality is objective and that man made laws need to be downstream of that.
All that to say, this isn't politics. It's a fight over the origin of right and wrong and weather or not you can justify harming others for what they say and think.