I like where you're going with that, EB. A Mexican immigrant applying for college here might be here illegally, but I can't think of many scenarios where I'd consider or could even see that to be morally reprehensible. I also don't like how we're assuming that no-one does anything to try and become a citizen once they get here. Besides, I think the notion that "Juan" just wants to take his degree back to Mexico is pretty silly. If someone's been living here illegally because their parents brought them here when they were young, and now they want to go to college, we should be making it as easy as possible for them to become citizens: not scaring them away from the process and making them think we're going to have them deported as soon as we find out they're here.
I also find some fault with the logic that illegal immigrants should be paying into these programs that they're benefiting from. I didn't realize that these sorts of programs were designed to financially dependent on people who live 10 to a room and work for weekly wages that most Americans lose in the wash.
Now, there is one angle where I can see the issue: what about the poor Americans who aren't getting help, because the help is going to non-Americans? I'm not sure how to answer that. I'll leave that one for someone else.
As an off-topic aside (that's gonna make me sound like a terrorist), don't quite a few states really belong to "Juan" anyway? This is throwing things way off-topic, and kind of a moot issue, but it's not like the US take-over of the Mexican territories was anything more than controversially justified.
I know raising that point is completely ridiculous, but I'm doing so to illustrate how silly our obsession over the Mexican border and keeping illegals out is. With the scope of history in mind, our hostility towards those people more native to this country than we (only 150 years after waging what was sort of an embarrassing war with them anyway) is going to look really bad in the next hegemony's textbooks. Frankly, we're at a point in our history where national borders should be increasingly less important. The paranoia over the Mexican border is something that I just outright do not understand.