"to do jobs Americans won't do."
This phase actually works for me. It's true. Perhaps you have not dealt with the industries that employ Mexican labor. For example, the meat industries - all the killing of animals, etc. etc. - it's not pleasant work - crops that require back breaking efforts to produce at harvest time, not pleasant work. Seasonal work; no benefits, no work some days, not pleasant if one has a family to support or even just rent to pay.
We should acknowledge that there are unpleasant jobs out there that no one would choose to do, unless one is at the bottom of the economic ladder or below. If fact, some American minory groups will not do the work outlined above - they would rather be on welfare or sell drugs.
We need Mexican labor, but only in a way that falls in line with our laws.
Americans have performed unpleasant jobs since it's creation. The only thing that has changed is that illegals are flooding in and working off of the books. That makes them cheaper than even an American citizen working for the same wage but on the books.
How can illegal aliens afford to do it?
susie