By Section I of Article II, it is declared that " The executive power shall be vested " in the President. By Section III it is required that " he shall take care that the laws are faithfully executed." In ultimate resort, then, all federal executive authority is in the President, and upon him lies the responsibility for seeing that the laws of the United States are faithfully executed, that is to say, that the armed and other forces of the Nation are, if necessary, employed to maintain in efficient operation the government of the United States over such districts as are under its sovereignty, and everywhere and under all circumstances, to protect its officers in the performance of their duties.

In fulfilment of the responsibility thus constitutionally imposed, the President has, by necessary implication, the authority to use all the specific powers conferred by the Constitution upon him. Chief of these is, of course, his authority as commander-in-chief of the land and naval forces of the Nation. He has also authority in many directions given him by statutes of Congress, with reference, for example, to the use of the militia, and to giving orders to subordinate executive officials.

Aside from these express powers, and those necessarily implied in them, the President has no other authority to act. That is to say, the obligation to take care that the laws of the United States are faithfully executed, is an obligation but confers in itself no powers. It is an obligation which is to be fulfilled by the exercise of those powers which the Constitution and Congress have seen fit to confer. At the time of the threatened resistance of the peoples of the Southern States to federal law in 1860, President Buchanan, under the advice of his Attorney-General, held himself practically powerless because of the lack of statutory authority to take the necessary steps. President Lincoln, upon his assuming office, gave a broader interpretation to existing laws conferring authority upon him, and Congress soon by statute, further increased his powers.

In earlier chapters has been shown how, by successive decisions of the Supreme Court, and by successive acts of Congress, the federal courts and the federal executive authorities have been empowered to extend full protection to all federal officials in the performance of their official duties, whether with reference to the punishment of those who have interfered with them, or the transference into federal courts, by habeas corpus, writs of error, or removal, cases in which federal officials accused of crime before state tribunals have set up, as a defense, that the act or acts with the commission of which they are charged were perfomed in connection with the exercise of, and justified by their authority as federal officers.