Mexico is an evenly divided society, as we are, but a powder keg. They are not complacent as we are. Mexico is ripe for a physical revolution. The last revolution, from 1910 to 1921, killed a third of the Mexican people -- few have been bloodier. Imagine the refugess swarming here from the next bloodletting of that magnitude! We will need more than a wall on our border; it is going to be really bad!
One reason that I'm worried about revolution in Mexico is that the last generation there with any real memory of the last revolution is rapidly passing away. Soon there will be no living memory of just how bad the last one was.