In the case of Tutun v. United States in 1925, the Supreme Court ruled that naturalization proceedings are not purely administrative but also judicial in nature. The petitioner, Radu George Tutun, was a Romanian immigrant who sought to become a U.S citizen while studying at Yale University. However, his application for citizenship was denied because he had not resided continuously within the United States for five years as required by law - he had spent some time abroad due to his studies and World War I military service. He appealed this decision all the way up to the Supreme Court arguing that exceptions should be made given his circumstances. The court unanimously held that it did not have discretion over naturalization cases and could only apply existing laws rather than interpret them based on individual circumstances or equity considerations. This meant they couldn't make an exception for Tutun despite acknowledging his good moral character and loyalty towards America. This ruling underscored two important principles: first, Congress has exclusive authority over immigration matters; secondly, courts must strictly adhere to statutory requirements when dealing with issues related to citizenship.

In the dissenting opinion for Tutun v. United States, Justice McReynolds disagreed with the majority's view that naturalization proceedings could be initiated outside of U.S. borders. He argued that Congress had not intended to grant such power and it was inappropriate for courts to infer this authority from ambiguous language in the law. He further contended that if Congress wished to extend these powers, they should do so explicitly through legislation rather than leaving it up to judicial interpretation. The justice also expressed concerns about potential abuses of such a system, including fraud or misrepresentation by applicants who were not physically present in the country during their naturalization process.