Immigration has a large history in the US, yes, but historically immigrants were encouraged (through social pressures) to assimilate part of their identity. Is that pressure for partial assimilation still there? Or do we encourage diversity so much now that anything goes?
> Or do we encourage diversity so much now that anything goes?
If anything it's the opposite. The US exports so much of its mainstream culture through movies, music, social networks and videogames that it's extremely difficult to find societies that are not heavily influenced by it.
In terms of culture, "globalization" meant "americanization" especially in the last 30 years.
I think this really depends on what we, as a society, want to ensure we all have in common. If you identify as a US citizen, what do you have in common with your countrymen?
Shared experiences and values can be hugely important. What those values should be is where I see a lot of contention.
I see this as a matter of degree. I think democratic values are fairly uncontroversial for a democratic country (rule of law, political representation, and all the other underpinnings of a function democracy). I think most US citizens also support many egalitarian ideals like the concepts of basic human rights, freedom of opportunity, and freedom of expression (speech, religion, etc).
That pressure still exists. I'm not sure why you might think otherwise. Various parts of current culture came from immigrant communities maintaining parts of their cultural identity while still broadly assimilating, eg St Patrick's Day.
Keep in mind a lot of immigrants from Central/South America 6 generations ago just pass for "white people" now so you don't notice them.
