The U.S. Supreme Court case Foley v. Connelie, Superintendent of New York State Police et al., 1977 revolved around the issue of whether a state could restrict employment in its police force to only U.S. citizens. The plaintiff, Thomas J. Foley, was an alien who had legally resided in the United States for several years and sought to become a trooper with the New York State Police but was denied due to his non-citizen status as per Section 215(3) of the Executive Law of New York which required citizenship for appointment into law enforcement roles. Foley challenged this requirement on grounds that it violated his rights under Equal Protection Clause of Fourteenth Amendment by discriminating against aliens without any substantial justification related to job performance or public safety concerns. However, the Supreme Court upheld this requirement ruling that states have significant interests in limiting certain government positions like those involving discretionary decision-making and execution of policy objectives - such as police officers - exclusively to citizens because they are directly linked with functions inherent in state sovereignty.

In the dissenting opinion for Foley v. Connelie, Justice Thurgood Marshall argued that the majority's decision to uphold a New York law barring non-citizens from serving as police officers was inconsistent with previous rulings on citizenship requirements for public employment. He contended that such laws should be subject to strict scrutiny under the Equal Protection Clause of the Fourteenth Amendment and found no compelling state interest justifying this discrimination against aliens. Furthermore, he criticized the majority's reliance on a distinction between "important" and "non-important" positions in determining whether citizenship is an appropriate requirement, arguing it lacked constitutional basis and could lead to arbitrary results. Finally, he expressed concern about potential harm caused by excluding qualified individuals based solely on their alienage.