Is that the type of "culture" that this statement is referring to?

> As long as you don’t have a common culture and a common understanding of the basic rules that everyone agrees on, no one can spend time with each other comfortably.

Doesn't seem so to me.

The center is mostly offline, thinks both extremes are very small portions of the population, and doesn't post on social media. So they seem small but really there are a lot of people like this who aren't shouting into the internet 24/7, so you just remember that what you hear is all the extremists shouting, not the people you saw during the course of a week who weren't.

Society is going bimodal on the 1% of issues that bisect people. Those 1% of issues are consuming 99% of our mass-media airtime.

Talk to your neighbors and you'll find that everyone just cares about decent roads, decent schools, decent jobs, and decent healthcare.

The central part of their identity is to assume that they're the vast majority of people. It allows them not to have to think about stuff too hard - it's all settled, and it's settled on what the people I'm exposed to (i.e. friends, family, and the television) think. I'm safe just repeating that and reporting people who deviate from that.

They don't realize how much the "moral majority" differs in town as opposed to the city, the coasts as opposed to the bulk of the country, in small private liberal arts colleges in the east and at Mormon universities in Utah, or in China, Russia, or Bulgaria as compared to the suburb they grew up in.

If all of those people simply follow the central tendency, and give mass media the same (or greater) weight as they give their neighbors, that guarantees war all the time. It will always be better to listen and try to understand points of view that you aren't familiar with, rather than to hide in the safe (and always untrue depending on the shape of the border you draw) assumption that you represent the vast majority. This, without even considering whether the vast majority are right or wrong.

I mean, some people are so impervious to reality with this that they can lose election after election and believe that they are still 95% of people. Then they start theorizing about mind control and supernatural entities, just to keep from opening their eyes and ears.

You are missing the point.

"Political issues" are by definition things that people disagree on. Saying people "disagree on political issues" is equivalent to saying "people disagree on things they disagree on."

But the vast majority of daily life is not driven by or meaningfully affected by any of these "issues on which people disagree." If you go and talk to your neighbors, even ones who you disagree with on disagreement-creating-topics, you will find you actually agree on nearly everything. The set of things you agree on is called "our culture."

I may be incorrectly inferring that you think this is a good thing, but "traditionally tribal humanity" were constantly at war with one another. I'm not sure that's something we want to go back to.

I’ll take more of that homogenization of culture please.