States offering in-state college tuition rates to illegal aliens -- but not to all American students -- are brazenly violating federal immigration law.

Currently, 12 states - California, Texas, New York, Utah, Washington, Oklahoma, Illinois, Kansas, New Mexico, Nebraska, Maryland, and Connecticut - are circumventing this unambiguous federal prohibition, while the Obama administration turns a blind eye to their violations.

Instead, it sues states like Alabama and Arizona for trying to assist the federal government in enforcing federal immigration laws.

In 1996, Bill Clinton signed into law the Illegal Immigration Reform and Immigrant Responsibility Act. Section 1623 of this statute prohibits state colleges and universities from providing in-state tuition rates to illegal aliens "on the basis of residence within the State" unless the state provides the same benefit to citizens regardless of their residence.

In other words, unless Maryland offers in-state tuition rates to students coming from, say, Pennsylvania and Virginia, it cannot offer in-state tuition rates to illegal aliens.

States like Maryland try to circumvent the express language and clear intent of Section 1623 by creating "alternative" criteria through which students can qualify for in-state tuition. Intended to act as a substitute for actual residence, these alternative criteria amount to nothing more than legal chicanery.

Doug Gansler, Maryland's attorney general, for example, claims that the state's new law does not violate Section 1623 because it does not require residence in Maryland - only that the student "attended" Maryland secondary schools for three years.

That ignores the fact that Maryland (like many other states) requires students to establish "proof of residency" for admission into public classrooms, K-12. In fact, one county (Prince George's) even requires a sworn "Affidavit of Disclosure" by parents verifying legal residency in Maryland.

It is clear that these 12 states are targeting illegal aliens for in-state tuition. While lawsuits challenging these state laws have not yet made it to the Supreme Court, the court has repeatedly struck down other state legislation clearly enacted to evade federal statutory or constitutional requirements.

One reason Section 1623 has not been reviewed by the Supreme Court is that at least one federal court of appeal has held that there is no private right of action to enforce this federal ban.

In other words, citizen university students and their parents who are being discriminated against by paying higher tuition cannot sue - only the U.S. Justice Department can. And the Justice Department has categorically refused to enforce this federal prohibition.

These state laws not only violate federal law, they force citizens to pay increased tuition since the burden of paying for the illegal alien beneficiaries is passed along to other students.

It is fundamentally unfair to make citizen students from out-of-state, as well as in-state taxpayers, subsidize the education of illegal aliens. It also provides an additional financial incentive to enter this country illegally. An August 2011 Rasmussen poll showed that 81 percent of voters oppose giving illegal aliens such benefits.

Citizens of states that provide in-state tuition rates to illegal aliens should be outraged at their legislators. The inaction of the federal government should also anger taxpayers.

Obama and Eric Holder, his Attorney General have an obligation to enforce the federal immigration laws passed by Congress. That includes enforcing the prohibition on state colleges and universities from providing in-state tuition rates to illegal aliens without extending the same benefits to other students -- students who are U.S. citizens.

This administration ignores the blatant violation of federal immigration law by 12 states, blesses "sanctuary" cities, and persecutes states that are stepping into the vacuum caused by the president's refusal to enforce our immigration laws. Such contempt for the rule of law should profoundly concern the American people.

Hans A. von Spakovsky and Charles D. Stimson are senior legal fellows in the Center for Legal & Judicial Studies at the Heritage Foundation.