From looks of things, Mexico would be just as good as US....why do they keep coming if poverty here is all they have to look forward to? I say close the borders....to all of them, and make everyone go through heavy process to obtain US residency.
People with no education at all, no ability to learn English, no jobs skills and who start families at age 14 or 15 are going to be "poor" where-ever they go --- but being poor in the USA means you get free food, free housing, free health care, free babysitting services and much more. In Mexico with no education, they might work hard for $25-30 a week and they would have to pay for the schools, health care, housing, and food that they get.
Being "poor" in the USA means you live like a queen and the government hands you more money than you could ever have imagined.