Americans can do the jobs, but some of the jobs, mexicans are more efficient. Like working in dairy parlors milking, or as horse grooms, picking fruit, masonwork, etc. I have worked with and have seen them work. many of them will work 65-70 hours a week just because they dont have anything else to do. I am all for allowing Immigrants coming in to work, but they need short term papers, and have to be out at the end of their time period.