The comment to my previous post deserves a lengthy response. As a Southern Californian who worked for a year in Mexico (as the only project member functionally illiterate in Spanish) I have heard the charge that ethnic Mexicans want to return the southwest United States (basically from Texas, Colorado, and California south) to Mexico. I know the Aztlan story.
Aztlan is like Atlantis, it is the mythical homeland of the Aztec people. Depending upon who does the speculating, the location of Aztlan is anywhere from the mid-Atlantic Ocean (Atlantis), the current Mexican state of Michoacan, Lake Powell in Utah, and even southern Wisconsin. If you are interested in the Atlantis myth, this website has way more than you will ever want to know. The Aztlan connection starts on page 13 with the various Western Hemisphere creation myths.
There is supposed to be a radical fringe among Chicanos who desire the reconquest of the Southwest United States by Mexico. I say "supposed to be" because the movement appears to be quite dead except with American xenophobes. The reconquest is outlined in "El Plan de Aztlan" written by Chicano students in the late 1960's. Like the Weather Underground and Black Panthers of the same era, this "plan" withered from a lack of interest decades ago. Unlike those other two groups, at its zenith it was never an armed struggle, in fact it was hardly even noticed outside a few Chicano Studies conferences.
The two main Chicano civil rights organizations are the moderate La Raza (the Race) and more radical MEChA (Chicano Student's Movement of Aztlan). Neither has a stated goal of reconquest. For them Aztlan is a cultural identity, not a revolutionary movement.
So, where does all the noise come from, how did "Anonymous" come by his views? Like the Protocols of the Elders of Zion, nativist radicals use Aztlan as a blood libel. Charges of invasion, reconquest, lawlessness, pestilence, and genocide have been attached to the word. The goal is simple race hatred. We have seen it all before. The Yellow Horde was going to overwhelm California; Jews caused the Black Plague by poisoning wells; then, of course, there is the history of the Blood Libel.
There is no organized attempt to reconquer parts of the United States. The border between the United States and Mexico is porous, but it has always been so.