There is a line in "Out Tonight" where Mimi sings "This city of neon and chrome feels too much like home when the Spanish babies cry." I kind of read that as her being of Hispanic/Latino decent and her name, Mimi Marquez, definitely reads as such.

As to Eric being a know-it-all... I don't remember now if "Hispanic" specifically denotes being from Spain. "Latino" means "from Latin America," which I used to believe meant only Central America, but it seems to encompass most of South America as well. "Chicano" is to be of Mexican and Native American decent.
This is all I remember from the happy musical presentation that we viewed in high school (Willmar, MN had a very large Spanish-speaking population).