Illegal Immigrant children do get free public education. Often free school lunches too.
If your a child and you're in the country you get free public education no matter your legal status.
The Supreme court ruled that such a law can't be passed since children while illegal immigrants have no choice in the matter. If their parents bring them over even knowing their children can't be schooled... the children are denied because the parents broke the law. That's deemed unacceptable in the US.
http://en.wikipedia.org/wiki/Plyler_v._Doe
This isn't the SOLE factor... but it is a very high confounding variable.








