The USA sold more goods to Mexico than to Brazil, India, Japan and Britain combined. 6 million American jobs depend on our trade with Mexico. Mexico bought 198 billion in US goods in 2011. American companies, like Costco and Walmart, are building numerous stores in Mexico. There is now a rising middle-class and Mexico is getting stronger economically. It's not all bloody streets and drug cartels. It would be nice if Mexicans had so much opportunity in their home country, there was little reason to come here. However, without Mexican seasonal laborers, many US crops will rot in the fields. That's what just happened in Georgia, when workers just up and left because they were afraid they would be deported. Believe me, I am sure Mexicans would rather be successful in their own country.
Alright... I have never been to mexico but, my mom went there she said there's lot's of... well "bad" people on the streets and things aren't as good as america at least in some places in america and mexico, also you know the the american history and the "Home of the brave and THE LAND OF THE FREE" and not exactly there's kind of nothing wrong with mexico. and also the "lies" :(
The wages are higher in the US compared to the wages in Mexico (and most other countries). Most people work in the US and send the money back to their home country so that their families can have a better life.
They are hardly the only ones. They're just more conveniently located than most. If you look around, there are people from MANY, MANY places. You may not realize it but you live (assuming you're from the US) in the greatest country in the world!