Sadly, the whole thing runs very deeply.
Case in point.
My partner's family is from Puerto Rico.
His father's side of the family are very light skinned.
His mother's family has some Indian blood, and are more brown, and he and his brother have inherited that trait.
Because of this, his paternal grandparents have never really acknowledged him and his brother - simply because he is darker skinned.
As I said, these people take it very seriously.
Ok, first, I am Mexican, loud and proud. Viva La Raza.
Second, if your partner doesnt recognize Mexicans as being Hispanic it is due to his own ignorance of the meaning of the term.
Puerto Rico, as well as Mexico, Cuba, all of Latin America, and all of South America with the exception of Brazil, was colonized by the Spanish. Without the mixture of native and Spanish blood, NONE of those nations would be considered Hispanic.
I am sorry that his grandparents dont acknowledge him because of his darker complection. That same prejudice exists in every Hispanic country. And sadly to say, if your partner doesnt consider other Hispanic nations to be truely Hispanic for whatever reason, he's being just as bad.
Finally, as for you assertion that Mexican illegals have no intentions of assimilating into our culture, have you ever asked yourself why?
Mexicans have ALWAYS been treated as second class citizens in this country. The education system in Mexico is not the strongest, and as such, most Mexicans come to this country with little to no knowledge of the English language. When they get here they are met with ignorance and intolerance, so why wouldnt they keep to themselves? And the truth is there are plenty of Mexican illegals who have definately attempted to assimilate into our culture. And when you see a Mexican on the street in American clothes, you still most likely think, dirty, lazy, or gang banger. One cant blame them for searching for a better life for themselves and for their children, but to say that they havent made the effort to become apart of our country is something that Americans themselves are just as responsible for.
And yet acceptance has never been Americas strong suit.