None of what you posted changes the fact that these nationalist Whites aren't native, and encroached on someone elses' land , then have the nerve to bitch about all the Brown and Black people in their midst. If they don't like it, they can move back to Europe, same goes for anyone else.
Most Mexicans and Central have significant indigenous ancestry , that makes them native if they so choose to identify as such. The borders are creations of colonial powers. Just because a person might have some White in him/her does not take away their native ancestry. There are a lot of North American natives with White ancestry, but that has never invalidated their claim to native tribal status. There are a lot of native tribes n Mexico and central America that barely mixed.