I would say the nation state is created through a dominant language, culture and ethnic group dominating a land mass

Politically and culturally

You could say French history is trying to make France French and is a reason for some of France's issues because in France you got to be French

For the USA it's very different due to its foundational myths and a nation founded by immigrants

The American dream and ideals are built into its system so it's a lot better at making foreign people's American

I remember reading some writing where it looks like the Latino Americans would be future Republicans

I not sure if it's between one or three generations

The point I am making us that American makes people American

The only real down side in the modern context not taking to consideration America's race politics and the Reckoning needing to happen with America's native Americans

Or indigenous people depending of which words you prefer

Their the culture of being anti British which makes sense with it being part of USA foundations