In the case of Elkins v. Moreno, the U.S. Supreme Court ruled in 1977 that a Maryland state policy was unconstitutional because it discriminated against out-of-state residents who held G-4 visas. The University of Maryland had implemented a policy requiring these visa holders to pay higher tuition fees than in-state residents, arguing that they were not technically "residents" as defined by their immigration status. However, the court found this argument unconvincing and stated that such discrimination violated both the Equal Protection Clause and Due Process Clause of the Fourteenth Amendment to the Constitution. This decision affirmed that all individuals residing within a state's borders should be treated equally under law regardless of their immigration status.

In the dissenting opinion for Elkins v. Moreno, Justice William Rehnquist argued that the majority's decision to strike down a Maryland law denying in-state tuition benefits to non-immigrant aliens was incorrect. He contended that there is no constitutional right for non-residents of a state to receive the same benefits as residents and that states should have discretion over their own residency requirements. Furthermore, he asserted that it is not inherently discriminatory or unreasonable for a state to differentiate between those who are likely to remain within its borders and contribute long-term versus those whose presence may be temporary. The distinction made by Maryland’s statute, according to him, was not based on alienage but rather on whether an individual has demonstrated intent of permanent residence in the U.S., which he believed did not violate equal protection principles.