The court held that it was within the competency of the President, and of the Attorney-General as the head of the Department of Justice, representing him, to direct that measures be taken for the protection of officers of the Government whilst in the discharge of their duties, and that it was specially appropriate that such protection should be given to the justices of the Supreme Court of the United States, whilst thus engaged in their respective circuits, and in passing to and from them; that the Attorney-General, representing the President, was fully justified in giving orders to the marshal of the California district to appoint a deputy to look specially to the protection of Justices Field and Sawyer from assault and violence threatened by Terry and his wife; and that the deputy marshal, acting under instructions for their protection, was justified in any measures that were necessary for that purpose, even to taking the life of the assailant.

The court recognized that the Government of the United States exercised full jurisdiction, within the sphere of its powers, over the whole territory of the country, and that when any conflict arose between the State and the General Government in the administration of their respective powers, the authority of the United States must prevail, for the Constitution declares that it and the laws of the United States in pursuance thereof “shall be the supreme law of the land, and that the judges in every State shall be bound thereby, anything in the Constitution and laws of any State to the contrary notwithstanding.”  The court quoted the language of the Supreme Court in Tennessee v.  Davis (100 U.S. 257, 263), that “It [the General Government] can act only through its officers and agents, and they must act within the States.  If, when thus acting and within the scope of their authority, those officers can be arrested and brought to trial in a State court, for an alleged offense against the law of the State, yet warranted by the Federal authority they possess, and if the General Government is powerless to interfere at once for their protection—­if their protection must be left to the action of the State court—­the operations of the General Government may, at any time, be arrested at the will of one of its members.  The legislation of a State may be unfriendly.  It may affix penalties to acts done under the immediate direction of the National Government and in obedience to its laws.  It may deny the authority conferred by those laws.  The State court may administer not only the laws of the State, but equally Federal law, in such a manner as to paralyze the operations of the Government.  And even if, after trial and final judgment in the State court, a case can be brought into the United States court for review, the officer is withdrawn from the discharge of his duty during the pendency of the prosecution, and the exercise of acknowledged Federal power arrested.  We do not think such an element of weakness is to be found in the Constitution.