Actually yes there are Caucasian or "white" Mexicans. They are of Spanish descent or are descendant from other European countries as many people from various countries did emigrate to Mexico, and Mexico was controlled by the French at one point a long time ago.

Italian/Italian-American culture is still around and IME it's just as strong as Mexican-American culture, various cultures from different countries who are living in the United States, African American/Black American culture, and Puerto Rican culture.