“Groups of people” doesn’t need to mean “ethnicity.” There’s a lot of political conflict in the Us, but it’s not primarily along ethnic or religious lines, for example. But there are groups of people, and they are different. Farmers in Iowa are different people than programmers in San Francisco. Having government necessarily requires those groups of people to make decisions about the lives of other people under the same government. That becomes exponentially harder as the group becomes more heterogenous with respect to the things governments do.
> But there are groups of people, and they are different. Farmers in Iowa are different people than programmers in San Francisco.
Again, I disagree with this. Plenty of programmers in San Francisco grew up on farms in Iowa. (And to be transparent about my biases here: my parents are Indian Christians, a distinct culture from the Hindu majority; my dad worked for ISRO; and I was born in the Deep South and worked as a programmer in SF for a few years. So the culture of "India" as a whole doesn't resonate with me, nor that of "the Deep South" or "SF" nor "America," and I don't feel like a lesser person for it.)
And I would claim that the fact that you can migrate from an area with one sort of politics / culture / economy / etc. to an area with another one (as a pointed example, anyone remember the "It Gets Better" videos from a few years ago featuring gay people who grew up across the country, half of whom seemed to say "and then I moved to San Francisco"?), and that people do that quite frequently, is evidence that there isn't much reason in attributing politics / culture / etc. to people as people in the way we've historically seen it, i.e., as correlated with place of birth or parentage or childhood culture, or proxies for those like religion.
If anything, the unrealistic part about Star Trek is that the various alien species had personalities influenced by their biology (the Vulcans with weaker emotional processing, the physically resilient Klingons, etc.). If they didn't, given pervasive interstellar transport, it's hard to see why so many people stay on their home planets. (And indeed the whole conceit of the Federation is that they don't have to.)
