You wouldn't be suggesting that we arm the peasant class in Mexico so they can overthrow their oppressors, would you? As soon as the WALL is built and the "flee north" safety valve is closed, the seeds of revolution will start to sprout. The only question being will they grow a free people or a "people's republic".
My bet is on the commies.
It's a mess no matter how you cut it. We want Mexican oil and Venezuelan oil. So how do we keep Mexico out of Hugo Chavez type commie hands? Do we allow another 30 million Mexicans to skate in here to release the social pressure?