[mikem170]

If a group of people can't reach consensus then the ideal may be to split into smaller groups, not force minorities to conform?

Nothing an HOA does is an emergency. Even if 2/3 of the people want to change the rules for parking, for example, they shouldn't get to screw over the people who bought the place without that rule and are vehemently opposed to such a change.

Scaled up to country size, like you mentioned, trying to get 330 million people to agree how the federal government allocates 25% of our national GDP turns out to be a big mess, especially when the slim majorities in congress change back and forth every handful of years. Maybe that's why the tenth amendment was put in place.

[pas]

There are shared/common resources. Environment (air, water, wildlife, etc.) There are stuff that cannot really be solved locally. Simply waiting and trying to persuade each other is very civil, but it has a cost. (Yes, it's very-very-very likely smaller than trying to usurp control with violence, but not every region/country is as fortunate as the US.)