See, what you, and others fail to realize is a very simple concept. The living conditions in Mexico are inumerably times worse than packing 30 people in a 2 bedroom apartment--to them that's much more livable than living in the desert with no roof over your head. And don't even give me the 'come here legally' line, because in reality, we all know how uneffecient this process is. At the rate we currently allow people to become legal [sometimes it can take 6 months to 1 year] it would take YEARS to legalize all immigrants that come in on a daily basis. So you're left with few options--speed up the system, become a xenophobic country, or do nothing. With the current administration the last option will probably be implemented. [It's been over 6 months since I've heard a SINGLE thing about solving the immigration problem from Bush]
Locking up our borders will just force the illegals to become more creative.