Washington (CNN) -- The Supreme Court has upheld a California law giving illegal immigrants living there reduced in-state tuition rates at public universities, the same rates legal state residents enjoy.
The justices without comment Monday refused to accept an appeal from out-of-state students attending California schools, who said it was unfair that as U.S. citizens, they had to pay as much as $20,000 more than illegal immigrants. They claimed such "preferential treatment" violated federal law.
The court decision is a victory for immigrant rights groups. California is one of a dozen states that make undocumented aliens conditionally eligible for in-state tuition, according to the legal brief filed by the suing students. Those various laws will remain intact for now.
The California law was passed a decade ago, and has been the subject of litigation ever since. It requires illegal immigrants to attend a California high school for at least three years, and to successfully graduate.
At issue is whether these state laws step on a congressional law limiting public education benefits for those in the country illegally. That 1996 federal law said "residence within a state" cannot be used as the basis to allow "any postsecondary benefit" -- including lower tuition rates -- unless all U.S. citizens would similarly benefit.
The California Supreme Court had unanimously ruled the state law relied on other important criteria -- especially the gradation requirement -- not residency, and was therefore proper. The out-of-state students had claimed in their appeal they were there were being discriminated against, by paying higher rates. They argued it was improper to deny U.S. citizens a benefit undocumented aliens are allowed. As in California, the difference can be significant. Full-time out-of-state students pay as much as five times more tuition than in-state counterparts at the various University of California campuses.
State education officials in their brief to the high court estimated about 41,000 students in 2010 benefited from the lower tuition, mostly those attending community colleges.
At the larger, four-year, state-chartered University of California system -- with its 10 campuses statewide, about 2,019 students paid in-state tuition in 2009 under the state law at issue. An estimated 600 were believed to be illegal immigrants, said the state.
The other states with similar laws are: Illinois, Kansas, Maryland, Nebraska, New Mexico, New York, Oklahoma, Texas, Utah, Washington and Wisconsin. Another dozen states have passed specific laws refusing in-state tuition for illegal immigrants.
Congress is considering a similar law, called the DREAM Act. It would speed citizenship for younger illegal immigrants who attend college or join the military.
Other states, led by Arizona, have passed legislation cracking down on undocumented residents. A statute currently under review by the federal courts would, among other things, give police authority to check a person's immigration status if officers have a "reasonable suspicion" that the individual is in the country illegally. The issue here is whether such state action steps on traditional federal authority over immigration matters.
The case turned aside Monday is Martinez v. Regents of the University of California (10-1029).