This section is from the book "The Constitutional Law Of The United States", by Westel Woodbury Willoughby. Also available from Amazon: Constitutional Law.
Whether or not a given person is to be recognized as the accredited agent, consular or diplomatic, of a foreign government, is, also, a question for final determination by the political department.14
13 In Doe v. Braden (16 How. 635; 14 L. ed. 1090) the court say: "It is said, however, that the King of Spain by the constitution under which he was then acting and administering the governments, had not the power to annul it by treaty or otherwise; that if the power existed anywhere in the Spanish government it resided in the Cortes; and that it does not appear, in the ratification, that it was annulled by that body or by its authority or consent. But these are political questions and not judicial. They belong exclusively to the political department of the government."
In Terlinden v. Ames (184 U. S. 270; 22 Sup. Ct Rep. 484; 46 L. ed. 534) the question was as to whether a treaty entered into between the United States and Prussia in 1852 was still in existence, although by the entrance of the latter country into the German Empire, it had ceased to be an independent State. The court held that the political departments of the United States had continued to treat the treaty as subsisting and that they were bound thereby, Baying: "Without considering whether extinguished treaties can be renewed by tacit consent under our Constitution, we think that on the question whether this treaty has ever been terminated, governmental action in respect to it must be regarded as of controlling importance."
14 Ex parte Baiz, 135 U. S. 403; 10 Sup. Ct Rep. 8.34; 34 L. ed. 222.