In many ways, the term "Caucasian" seems to be a very archaic term, especially when considering that theoretically race is a social construct but you'd be surprised how many people in the U.S., particularly those who categorize themselves as white, refer to themselves as white and Caucasian, almost interchangeably.
My point (challenge, if you will) to the poster that I originally replied to is that I have never personally known anyone who identifies as Latino/Latinx claim that their culture or identity was with Spain. I grew up with Puerto Ricans, Dominicans, Colombians, Mexicans/Chicanos, Panamanians and I never heard that before. In fact, the majority of those I have known looked at Spain as having colonized their respective countries/islands. Even the issue of language is fraught. If you've ever been to Spain, you will find that those who willingly speak Castilian (and honestly, that is not everybody, there are some ethnic groups that are fairly resistent to Spanish/Castilian culture and language) speak quite differently from someone in say...Cuba or Mexico, who each have their own idioms. Try going to Cuba or Mexico or Panama and addressing an elder person by saying ¡Oiga! like you'd do in Spain and see what reaction you'd get. I myself would never do this outside of Spain but I'd bet that the reaction wouldn't be very good.