nbclatino.com has a story about an art exhibit portraying superheroes as illegal immigrants. The whole concept of this piece is amazing, but some of the comments on the story are also priceless.
"… to be fair Betsy Braddock (Psylocke) may have some irregularities in her immigration paperwork as she was originally a white british woman who is now trapped in the body of a Japanese woman. Is there a form for that?"
Wonder Woman is debatable because she has been the official ambassador for Themiscyra before but she has also illegally pretended to be a citizen of the US as Diana Prince.
There was also one commenter that brought up the fact that Aquaman and Namor are both rulers of their own countries and have at various times been recognized as ambassadors by the US, which I couldn't find again but it was pretty great I assure you.