The powers of the President as Chief Executive derive from the Article II, Section 1 of the Constitution, which states: “the executive powers of the United States shall be vested in the President of the United States." Section 1 goes on to specify the Presidential Oath, in which the President promises to "faithfully execute the Office of the President of the United States, and will to the best of my ability, protect, and defend the Constitution of the United States." In addition, Section 3 requires that he or she "take care to see that the laws [are] faithfully executed."
The bounds of executive power have been debated since the first presidency. The center of the debate has been this: to what extent can the Congress give direction to executive department officials? Presidents have held that members of the executive branch cannot be made to act against the will of the President. Caleb Cushing, Attorney-General under President Franklin Pierce wrote:
"I think here the general rule to be that the Head of Department is subject to the direction of the President. I hold that no Head of Department can lawfully perform an official act against the will of the President; and that will is by the Constitution to govern the performance of all such acts. If it were not thus, Congress might by statute so divide and transfer the executive power as utterly to subvert the Government, and to change it into a parliamentary despotism."
The courts have not always agreed with this sweeping interpretation of executive power. In the case of Kendall v. the United States, the Supreme Court wrote: "The executive power is vested in a President; and as far as his powers are derived from the Constitution, he is beyond the reach of any other department except in the mode prescribed by the Constitution through the impeaching power. But it by no means follows, that every officer in every branch of that department is under exclusive direction of the President. Such a principle, we apprehend, is not and certainly cannot be claimed by the President."