The duty imposed upon him [the president] to take care that the laws be faithfully executed, follows out the strong injunctions of his oath of office, that he will 'preserve, protect, and defend the Constitution.' The great object of the executive department is to accomplish this purpose; and without it, be the form of government whatever it may, it will be utterly worthless for offence or defense; for the redress of grievances or the protection of rights; for the happiness, or good order, or safety of the people.
Joseph Story