The more interesting scenario to consider, IMHO, is a civil war between a controlling but “not the US” majority, and a resisting minority. For example: what would happen if there were a modern Red Scare, but one with a basis in reality—i.e., if somehow >50% of the US (including our political leaders) were subverted by China, became believers not just in Communism but in the CCP’s propaganda about Communism necessitating political unification and erasure of separate cultural identity, and so the belief that the US should volunteer to be annexed+absorbed by China?
If the majority of the US believed that... what should the rest of us do, at that point, to stop this from happening? Is the correct answer just “the US is a democratic nation, so if the majority of the population wants the US to stop being a democracy, that’s the ‘democratic choice’, and if you believe in the ‘power of democracy’, you should support it”?
The US is not a democracy and you have just outlined why. Small autonomous regions were created to limit external influence and allow people to live their lives in peace. A lot of stuff now happens on the national level that was never meant to happen on the national level.
The United States is a democracy. Democracy does not mean only direct democracy. Representative democracy, democratic republics, and federalism are forms of government compatible with democracy.
https://reason.com/2018/01/17/the-united-states-is-both-a-re...
The first link implies that somewhat, but I would guess we need a historian to map the meaning over time.
But that is kind of besides the point. A lot of people are arguing "they may have overwhelming force, so roll over and give them what they want." No thanks?