In the background image you can read a little excerpt from chapter 19 of John Steinbeck's "The Grapes of Wrath".
"Rattlesnakes! Don’t take chances with ’em, an’ if they argue, shoot first. If a kid’ll kill a cop, what’ll the men do? Thing is, get tougher’n they are. Treat ‘em rough. Scare ‘em."[[http://www.thepriceoftreason.net/images/price_02.jpg]]
This novel shows that those Mexico references are not a coincidence. In this book you can see the Joad family fleeing from Oklahoma to California looking for a better place to live... sounds like immigration to me. And in some point, that book tell us what happened to all that territory that once was part of Mexico... just the half of what used to be our country (México).