Actually, NAFTA has caused more illegal immigration. Many small Mexican farmers were driven off the land by Mexican companies trading with the US because of NAFTA-these people had no jobs and no where to go so they headed across the border. NAFTA increased illegal immigration.
The Mexican people now have access to lower cost food and greater variety and you think that's bad for them? Do you think higher priced food is beneficial to the people who can least afford it? If we built a fence along the border and truly punished businesses who knowingly hire illegals we wouldn't have such a problem with illegals from Mexico. Your problem is with the weak kneed politicians who won't protect our borders; not with a trade agreement that has benefited all parties.