A federal judge has ruled the state is discriminating against potentially thousands of U.S. citizens who live in Florida, by charging them higher out-of-state tuition as non-resident students simply because their parents may lack legal U.S. residency.

U.S. District Judge K. Michael Moore found Tuesday that Florida’s rule classifying such students according to their parents’ undocumented immigration status violates the Constitution’s equal protection provision.

“By virtue of their classification, [these Florida students] are denied a benefit in the form of significantly lower tuition rates to the state’s public post-secondary educational institutions,” the judge found in a 19-page opinion that was highly critical of the state’s policy.

“This creates an additional obstacle for [them] to attain post-secondary education from one of the state’s public institutions that is not faced by other residents.”

Moore, who was nominated by President George H.W. Bush and confirmed in 1992, further found the policy “does not advance any legitimate state interest, much less the state’s important interest in furthering educational opportunities for its own residents.”

The state’s Department of Education said it has received the judge’s ruling and is reviewing it.

The Florida students’ lawsuit was filed in October 2011 by the Southern Poverty Law Center. The center represents students who are U.S. citizens and Florida residents, including several from Miami, but whose parents cannot prove legal immigration status.

Florida’s policy is the result of administrative rules created in 2005. Though state law deals with tuition residency issues, it delegates the responsibility to draw up specific rules to the Department of Education (for community colleges) and the Board of Governors (for state universities).

The Southern Poverty Law Center estimated hundreds or thousands of Florida students could be affected by the judge’s ruling. As the policy stands, students who are classified as “non-residents” in Florida can be charged more than triple the cost of in-state tuition. The policy affects those under age 24 and who are claimed as dependents by parents.

The center, based in Montgomery, Ala., hailed the judge’s decision.

“Today is a great day for these young people across the state of Florida who simply wanted the opportunity to get an education and, with that, a chance for the American Dream,” said the center’s deputy legal director, Jerri Katzerman.

“This policy, which was blatantly unconstitutional, will no longer be a roadblock for these young students who may very well be the state’s leaders of tomorrow.”

“Every year Florida graduates thousands of students, many of whom face an uncertain future due to legal restrictions or insurmountable financial burdens because of their immigration status,” Miami-Dade Schools Superintendant Alberto Carvalho said Tuesday.

“Today’s ruling represents a return to reason and the opening of the door of opportunity for deserving students who want nothing more than to give back to the only community and nation that they have ever known.”

In the case of Wendy Ruiz, who was born and raised in Miami, the state’s policy has created a financial hardship for the U.S. citizen. In the eyes of Florida’s higher education system, she’s a dependent student whose parents are undocumented immigrants — and not considered legal Florida residents.