I've observed strong bonds are formed during hardship, so enduring the teenage years/military service/some other hardship with others will result in a deeper friendship, but people are moving around so much that even if you have such bonds the other person will likely move to another city.
Nearly all political persuasion is framed as a moral argument and dissenters are publicly shamed. Eg. You are a bad person if you drive a SUV. This is not just a property of the left
> Nearly all political persuasion is framed as a moral argument
That's because most political disagreement is disagreement on moral first principles (it often includes disagreement on facts, but that's rarely the root of the divide.)
It's interesting that the things from xorcist's post that I think you are calling vestige of Christian morality - being anti abortion, music, art, vaccinations and science - have almost nothing to do with the teachings of Christ or much to do with morality. I'm not sure how you'd categorise those - perhaps a witch doctor style veneration of mumbo jumbo over reason for political purposes. Kind of, you must believe my smoke and bones cure all or you are an evil heretic, type stuff.
The narrative in this country is people who dont agree with the liberal establishment are mentally ill in the form of racism, sexism, etc. This is the level of political discourse we put up with.