Part of me wonders if having an American accent should be part of this conversation. Accent is logically distinct from race and something you can quickly assess someone for (unlike most items on this list). And pragmatically speaking, a standard accent is helpful for communication. If we truly need some sort of in/out boundary, we could do worse than accent.

I’m not sure if we really need that us/them boundary. But if people must discriminate, I would rather they e.g. discriminate against Indians who specifically have an Indian accent, as opposed to US-born Indian-Americans who just have Indian ancestry.

You can even teach yourself a new accent as an adult if it matters that much to you. But an American accent is always a sign of something: You grew up in the US, or you grew up with a lot of American media, or you really wanted to become American (or succeed as an actor/influencer lol).

The irony here is that Americans tend to not think of themselves as having an accent. Relative to the size of our population and geography, our language use is remarkably uniform. Maybe that could be a useful asset for national-definition purposes.