It's called "Exodus: The ominous push and pull of the U.S.–Mexico border" by Marc Cooper.
This is the part that just blew me away:
With an estimate 11-to-1 manufacturing wage differential between the two countries (some experts put the agricultural wage gap at twic that), why is anyone shocked by what's happening? "You're looking at the biggest story of our lives," Bowden told me over dinner. "This is the largest cross-border human migration in history." Though rarely, if ever posed in those terms, the staggering numbers tend to bolster Bowden's sweeping vision. Something like 15 to 20 million migrants have crossed into the United States over the last two decades. An equal number are expected to do so in the next twenty years. "People aren't coming here as much as they are leaving a cratered economy," Bowden said. "The only way you'll stop Mexicans coming to the U.S. is if you lower American wages to the same level as Vietnam. Someone worth maybe $100 a month in Mexico who comes to the U.S. becomes a human ATM machine. McCain-Kennedy, Kyl-Cornyn?" he said, referrig to the hodge-podge of current immigration-reform proposals. "It's all bullshit. What we're seeing is something right out of the Bible. This is an exodus."Bowden's book is called Down by the River.