The kids are AMERICANS, trying to be part of the American culture and not their parents' culture. I agree that it sucks that the parents aren't paying property taxes to help fund schools, but at the same time, we can't turn our backs on American kids because their parents don't have HOW TO do it the correct thing (live here, pay property taxes, etc.)
People may argue that the correct thing, then, would be for the kids to go to school in Mexico, but why would they want to do that? American schools are so much better, and kids will be learning about American history (instead of Mexican history), for example.
Besides, doesn't the government help a lot of Americans who don't pay any form of taxes anyway? :shrugs: