My wife is a legal immigrant. We went through a whole lot of grief to get her here legally. By law she cannot receive any means-tested federal money. By law, illegal immigrants can receive means-tested federal money. For example, if we were poor and needed WIC to help feed our baby, we couldn't get it, but some woman who snuck across the border could. The WIC site specifically mentions that illegal (sorry, "undocumented") immigrants are entitled.
How FUBAR is that?