“America” is Anglo-America, the heritage ethnic stock from the British Isles, with some Continental admixture. Anglo-America includes other groups, but they assimilated to the Anglo-American supermajority and not the other way around. When Anglo-Americans are no longer the majority, a future that has already been born, the place may still be called America but it will be a different country.

If the federal American government were ever to collapse, the Angelenos, the Tejanos, and others would be their own nation-state faster than you can say blood is thicker than water.