Most of the illegal migrants from Mexico pass through Arizona. The 'Arizonians' have become a bit fed up with this so they've just passed some laws that enable the police to stop and question anyone they suspect of being a filthy dago... This law is somewhat draconian and empowers police to harass anyone they don't like the look of, basically. So, don't go wandering around Arizona wearing a poncho or speaking like Speedy Gonzales.
In a neat little twist, however, Chief Standing Wolf of the Navajo has issued a statement pointing out who are the original residents and has issued a warning “reverse your laws entitling only English-speaking people to inhabit Arizona. Only then will we back down and allow peace to again grace Arizona, but if you deny our fellow red and brown men their rightful place in this state, there will be bloodshed.” Of course, Chief Standing Wolf was speaking in his native tongue, so the lawmakers in the State weren’t exactly sure what the message was. (via eons).
Another point is that these Mexicans are only looking for work - they don't intend to steal anybody's land or wipe out the local population.