Should the U.S. be a model universal nation? Why or why not?

I think the United States is actually a universal model, like us or don't.  As many of the articles we have read, we see that the U.S. is a diverse country where we can find people from any part of the world, in some big cities like California or New York we can find persons talking in many different languages than English, people are also practicing their own practical cultures, for example people from Taiwan or Mexico have big parties to remember their traditions and I believe this kind of practices make them have present, their own identities in a country like the U.S.
What I think is not a good model about this country is the Foreign Policy that uses with other nations, and maybe this country could learn about others in issues like Health because many people can not afford and benefits of it.
But, definetely this country has good things like the huge diversity of people, living in the U.S. we could learn to be more tolerating to others and be respectful, for that reason I think this country is actually a universal model, I know that not all people are respectful about others, but I believe that we can keep learning to share the same home together or like Martin Luther King Jr. termed ""a world house", a commitment to a society of inclusion." Finally, this country could be a model and a good example for other nations that have diversity in culture, religions or race.