The Nahuatl word Mēxihco is composed of the root Mexi and a suffix -co that means "place" or "city." The full name of the city, Mexico-Tenochtitlan, means "the place of the Mexica among the stone-cactuses," - they never were in the Southwest because, as I mentioned, the Indians there would have thrown them out.
No argument there; you were saying that they are ALL Spanish descendants. All I was saying is that there are a good many without a drop of Spanish blood.