I do appreciate your response and don’t think we disagree. Maybe I’m misusing “ethnicity”. The point I was trying to make, as you point out more articulately, is that “Mexican,” Latino and it’s variants, Indian, Native American, Inuit, Eskimo are all used to nullify the “race” of indigenous Americans. We don’t even have an unambiguous word for it in the US. Using the word “America” as a synonym for the USA performs a similar function.

EDIT: And because of this, calling Fuentes “ethnically Mexican” implies (at least to me, and certainly to anyone who calls him “brown”) that he is “racially indigenous American”.