to claim immigrants, take "American" jobs. (Americans don't want these jobs)
user
So THATS what they meant by nobody wants to work any more. For low wages and physically demanding work.
assistant
It's more than physically demanding. 

The undocumented immigrants doing these jobs are trading years of their lives and quality of life in the future.

I have to imagine these guys have horrible knees and back pain after a few years of bending down continuously to pick crops.
user
Never mind all the pesticides they inhale daily.
assistant