Allowing illegal aliens to pay in-state tuition is a violation of federal law!

http://www.law.cornell.edu/uscode/text/8/1623

(a) In general Notwithstanding any other provision of law, an alien who is not lawfully present in the United States shall not be eligible on the basis of residence within a State (or a political subdivision) for any postsecondary education benefit unless a citizen or national of the United States is eligible for such a benefit (in no less an amount, duration, and scope) without regard to whether the citizen or national is such a resident.
(b) Effective date
This section shall apply to benefits provided on or after July 1, 1998.

8 U.S. CODE § 1623 - LIMITATION ON ELIGIBILITY FOR PREFERENTIAL TREATMENT OF ALIENS NOT LAWFULLY PRESENT ON BASIS OF RESIDENCE FOR HIGHER EDUCATION BENEFITS

http://www.law.cornell.edu/uscode/text/8/1623