Illegal Mexicans inmigrats in the USA

This is the most polemic problem between Mexico and USA, Why Mexicans hate Americans?. Because the American people make to feel Mexicans like a dogs, and the Mexicans inmigrants just want to get a better job, and those jobs that the Mexicans are doing in USA any traditional American do it. In my opinion, if USA doesn't have the Mexican people that are working for them, the Economy will be crash if the poor people or undocumented people leave USA. Altought, the Mexican workers are sending money back to Mexico and the American government said that its a economic problem, but i think the opposite, that's a balance. Most of the American companies that are establishing in Mexico are sending the money back to USA and those companies are increasing their profit as Mexicans. So that is the balance between USA and Mexico. USA government they said that Mexico is a problem for them, why???, the Mexican people who work in the USA are not criminals, they are doing works that any Americans don't or cant do. I think both governments need to work together to fix that problem. I think this a big problem between borders in the world, not just in Mexico-USA.