I could never understand why Mexico is so screwed up. Stories like this one explain everything.
America has the 'best' and most expensive military the world has ever seen. If we wanted to stop the vast majority of illegal immigration from Mexico, we could. But we don't want to. It serves the business class to have cheap labor running throughout the country.
I never understood why we just don't have military bases along the boarder. Use the miles of open space as a firing range for tanks, aircraft ans so on, that should take up many miles right there.