you have businesses like restaurants and hotels - and all you hear from them is whining that "americans won't fill our jobs", "we need these illegals". why aren't they out there in the "marketplace" filing those jobs by offering wages to attract people?
These are basically minimum wage jobs you are describing. So mainly these jobs go to people just entering the job market who are unskilled. Kids and illegals.
The pool of this category of workers is very large. If there were no illegals, these jobs would go to teenagers, like they obviously do in places where there are no illegals.
So to venture a guess as to why they cry "we need these illegals". It could be that they are paying them less than minimum wage. Which many surely are because the restaurant business is very hard to succeed in. Very slim profits. Or it could be that it is not the restaurantuers doing the crying, but the politicians.