In the 1890 United States v. Ewing case, the Supreme Court ruled on a dispute over property rights and jurisdiction in Oklahoma Territory. The plaintiff, Ewing, had purchased land from Native Americans who were given authority to sell their lands by Congress. However, the defendant argued that this sale was invalid because it violated an existing treaty between those tribes and the U.S government which prohibited such sales without federal approval. The court held that while treaties with Native American tribes are indeed laws of the land under Article VI of Constitution, they can be superseded by subsequent acts of Congress if there is clear intent to do so. In this case, since Congress had explicitly granted these tribes power to sell their lands in later legislation (the Indian Appropriations Act), it effectively nullified any conflicting provisions in earlier treaties prohibiting such sales without federal consent.

In the dissenting opinion for United States v. Ewing, it was argued that the majority's ruling failed to properly consider and apply constitutional principles of due process. The dissenting justices believed that Ewing had been denied his right to a fair trial because he was not allowed to present evidence in his defense regarding the alleged fraudulent activity. They contended that this denial violated fundamental fairness under the Fifth Amendment’s Due Process Clause, which guarantees individuals their day in court and an opportunity to defend against charges brought by government prosecutors. Furthermore, they disagreed with how broadly the majority interpreted federal law related to mail fraud, arguing such interpretation could potentially criminalize innocent conduct or actions taken without intent of defrauding anyone. This expansive reading of statutes also raised concerns about separation of powers as it seemed like judicial overreach into legislative territory.