Trump DOJ sues university where illegal immigrants can get $15K tuition rate while some Americans pay $42K

Additionally, it says the policy is independently unlawful under 8 U.S.C. §1621 because the benefit was established through university policy rather than an enacted Delaware state law. DOJ describes the policy as being "preempted twice over," and also calls the policy "blatant unequal treatment."

"This Department of Justice's efforts will not cease until we have challenged every state law or university policy that gives preferential treatment to illegal aliens over our nation's own citizens," Stanley E. Woodward Jr., associate attorney general, said in a statement.

"Congress long ago made clear that states cannot give reduced tuition to illegal aliens not available to all Americans," he added. "When a state attorney general allows her own state to violate federal law, this department must step in to enforce it."

In a statement to Fox News Digital, the University of Delaware said, "The University of Delaware is aware of the complaint filed last week by the U.S. Department of Justice, and we are reviewing it carefully. Because this is a pending legal matter, we will not comment further at this time."

Fox News Digital reached out to the Department of Justice for comment.