A few bucks a day for a low skilled peasant buys a lot of political security when close to 700 million people may be apt to show their unhappiness at living conditions or crummy food.
I suspect Bush's refusal to stanch the Latin flood is because he fears a Mexican revolution if we don't drain off the disaffected population. So we are getting the restless millions here. At some point I think those millions will realize that conversion to Islam will give them Aztlan from the Rio Grande to Kennebunk. Then we will go to 40-100 million saracens in a couple of years and sharia will be a looming presence.