These jobs that "Americans won't do" should be filled by y9ooung Americans, teens and college students. Employment is a learned behavior. I hire people all the time and you'd be surprised how many young people who enter the workforce who have never had a job and don't understand the work environment. Practices such as coming to work on time, showing up every day, ethical honest work habits, productivity. So many of the young people I have hired think they are in the building (at work) they are do pay- even if they are not productive. I'd rather train a young person the ethics of work at a minimum wage busboy job then to try to explain the basics to a kid who has a degreee in civil engineering but thinks a two hour lunch is OK.
If not young people, then people who are holding down one medium pay job and need another part time job to get ahead. There is no reason to give jobs to anyone other then Americans in America.
What are these jobs that "Americans won't do" and who are these Americans that won't do them? And why won't they do them? Why is it that Mexicans can them and live? I don't understand. What are these Americans that won't them doing instead?