The Republican contention was that murder and robbery (seizure of ships) constituted piracy "by the law of nations," and that, therefore, Nash should have been indicted and tried by American authority as a pirate; whereas he had been delivered to Great Britain as a criminal against that nation.

But, said Marshall, a single act does not necessarily indicate piratical intent unless it "manifests general hostility against the world"; if it shows an "intention to rob generally, then it is piracy." If, however, "it be merely mutiny and murder in a vessel with the intention of delivering it up to the enemy, it" is "an offense against a single nation and not piracy." It was only for such murder and "not piracy" that "Nash was delivered." And, indisputably, this was covered by the treaty. Even if Nash had been tried and acquitted for piracy, there still would have remained the crime of murder over which American courts had no jurisdiction, because it was not a crime punishable by international law, but only by the law of the nation in whose jurisdiction the crime was committed, and to which the criminal belonged.

American law and American courts could not deal with such a condition, insisted Marshall, but British law and courts could and the treaty bound America to deliver the criminal into British hands. "It was an act to which the American Nation was bound by a most solemn compact." For an American court to have convicted Nash and American authorities to have executed him "would have been murder"; while for them to have "acquitted and discharged him would have been a breach of faith and a violation of national duty."

It was plain, then, said he, that Nash should have been delivered to the British officers. By whom? The Republicans insisted that this authority was in the courts. Marshall demonstrated that the President alone could exercise such power. It was, he said, "a case for Executive and not for judicial decision." The Republican resolutions declared that the judicial power extends to all questions arising under the Constitution, treaties, and laws of the United States; but the Constitution itself provided that the judicial power extends only to all cases "in law and equity" arising under the Constitution, laws, and treaties of the United States.

"The difference was material and apparent," said Marshall. "A case in law or equity was a term well understood and of limited signification. It was a controversy between parties which had taken a shape for judicial decision. If the judicial power extended to every question under the Constitution, it would involve almost every subject proper for Legislative discussion and decision; if to every question under the laws and treaties of the United States, it would involve almost every subject on which the Executive could act. The division of power ... could exist no longer, and the other departments would be swallowed up in the Judiciary."

The Constitution did not confer on the Judiciary "any political power whatever." The judicial power covered only cases where there are "parties to come into court, who can be reached by its process and bound by its power; whose rights admit of ultimate decision by a tribunal to which they are bound to submit." Such a case, said Marshall, "may arise under a treaty where the rights of individuals acquired or secured by a treaty are to be asserted or defended in court"; and he gave examples. "But the judicial power cannot extend to political compacts; as the establishment of the boundary line between American and British Dominions ... or the case of the delivery of a murderer under the twenty-seventh article of our present Treaty with Britain....

"The clause of the Constitution which declares that 'the trial of all crimes ... shall be by jury'" did not apply to the decision of a case like that of Robins. "Certainly this clause ... cannot be thought obligatory on ... the whole world. It is not designed to secure the rights of the people of Europe or Asia or to direct and control proceedings against criminals throughout the universe. It can, then, be designed only to guide the proceedings of our own courts" in cases "to which the jurisdiction of the nation may rightfully extend." And the courts could not "try the crime for which Thomas Nash was delivered up to justice." The sole question was "whether he should be delivered up to a foreign tribunal which was alone capable of trying and punishing him." A provision for the trial of crimes in the courts of the United States is clearly "not a provision for the surrender to a foreign Government of an offender against that Government."

If the murder by Nash were a crime, it is one "not provided for by the Constitution"; if it were not a crime, "yet it is the precise case in which his surrender was stipulated by treaty" which the President, alone, must execute. That in the Executive decision "judicial questions" must also be determined, argued nothing; for this often must be the case, as, for instance, in so simple and ordinary matter as issuing patents for public lands, or in settling whether vessels have been captured within three miles of our coasts, or in declaring the legality of prizes taken by privateers or the restoration of such vessels—all such questions, of which these are familiar examples, are, said Marshall, "questions of political law proper to be decided by the Executive and not by the courts."

This was the Nash case. Suppose that a murder were "committed within the United States and the murderer should seek an asylum in Great Britain!" The treaty covered such a case; but no man would say "that the British courts should decide" it. It is, in its nature, a National demand made upon the Nation. The parties are two nations. They cannot come into court to litigate their claims, nor can a court decide on them. "Of consequence," declares Marshall, "the demand is not a case for judicial cognizance."

"The President is the sole organ of the nation in its external relations"; therefore "the demand of a foreign nation can only be made on him. He possesses the whole Executive power. He holds and directs the force of the nation. Of consequence, any act to be performed by the force of the nation is to be performed through him. He is charged to execute the laws. A treaty is ... a law. He must, then, execute a treaty, where he, and he alone, possesses the means of executing it."