Inherent powers refer to those powers over and beyond those explicitly spelled out in the Constitution or which can reasonably be implied from express grants. It is the authority possessed implicitly without its being derived from another. The power may be owing to the nature of sovereignty or to a permissive interpretation of the language of the Constitution.
In the American constitutional system, the existence of inherent powers has always been a contested point. Those opposed to the concept of inherent powers argue that the government and all its officers derive their authority from the Constitution, whose terms contain all the powers that the people intended to grant. Those in favor of inherent powers support it on account of the language of the vesting clauses of Articles I and II of the Constitution, or from the role of the chief executive as commander of the armed forces and as the official primarily responsible for the maintenance of law and order, or from the status of the president as head of a sovereign nation.
The Supreme Court generally tries to find authority for governmental acts in the Constitution. However the court has also been reluctant to insist on narrow interpretations of the executive powers granted by the Constitution. The U.S. Supreme Court has discovered federal inherent powers to take land through eminent domain proceedings, to acquire land by discovery and occupation, to exclude or admit aliens, and to sell munitions to belligerent nations.