Nine states (CA, NM, WA, UT, TX OK, KS, IL and NY) have laws allowing certain illegal aliens to get college tuition at the discounted, in-state rate. Bills have been proposed in other states (for instance, Massachusetts) and even in the U.S. Congress (Orrin Hatch's DREAM Act), and they're supported by dozens of politicians. The news media does its job, publishing what amounts to pure propaganda: an endless series of sob stories and completely biased reporting (two very similar examples side-by-side).

One way to fight this is through the courts: here, here. Those states listed above are probably in violation of a federal law; the catch is that a judge recently ruled that only the DHS can enforce that law. That ruling is being appealed, and the DHS has so far refused to do their job despite repeated requests.

A perhaps easier way to fight this is by discrediting anyone who supports it. As it turns out, that's quite easy, since in-state tuition for illegal aliens is completely indefensible. All you need to do is ask a supporter:

Why do you support taking discounted college educations away from U.S. citizens and giving them to citizens of other countries?

There are only a finite number of colleges and only a finite number of discounted college educations available. And, there will always be more applicants than discounts. Every discount given to an illegal alien represents a discount that could have gone to a citizen or legal immigrant, but did not. In effect, this results in taking educations away from citizens and legal immigrants, and giving them to people who are not citizens and are not here legally. While some might certainly try, no one is going to be able to successfully defend doing that.

The only problem now is getting the word out. For that, I suggest you visit forums where candidates speak and ask them the question above. And, if you see a newspaper publishing a sob story in support of the DREAM Act or similar, send their ombudsman that question. Let's see how their emotionalism stands up to the facts.