Constraints on Presidential power
Because of the vast array of presidential roles and responsibilities, coupled with a conspicuous presence on the national and international scene, political analysts have tended to place great emphasis on the president's powers. Some have even spoken of "the imperial presidency," referring to the expanded role of the office that Franklin D. Roosevelt maintained during his term.
One of the first sobering realities a new president discovers is an inherited bureaucratic structure that can be difficult to manage and slow to change direction. The president's power to appoint extends only to some 3,000 people out of a civilian government work force of about 3 million.
The president finds that the machinery of government (the civil service) often operates independently of presidential interventions, has done so through earlier administrations, and will continue to do so in the future. New presidents are immediately confronted with a backlog of decisions from the outgoing administration. They inherit a budget formulated and enacted into law long before they came to office, as well as major spending programs (such as veterans' benefits, Social Security payments, and Medicare health insurance for the elderly), which are mandated by law. In foreign affairs, presidents must conform with treaties and informal agreements negotiated by their predecessors in office.
As the happy euphoria of the post-election "honeymoon" dissipates, the new president discovers that Congress has become less cooperative and the media more critical. The president is forced to build at least temporary alliances among diverse, often antagonistic interests — economic, geographic, ethnic, and ideological. Compromises with Congress must be struck if any legislation is to be adopted. "It is very easy to defeat a bill in Congress," lamented President John F. Kennedy. "It is much more difficult to pass one."
Despite these constraints, every president achieves at least some of his legislative goals and prevents by veto the enactment of other laws he believes not to be in the nation's best interests. The president's authority in the conduct of war and peace, including the negotiation of treaties, is substantial. Moreover, the president can use his unique position to articulate ideas and advocate policies, which then have a better chance of entering the public consciousness than those held by his political rivals. President Theodore Roosevelt called this aspect of the presidency "the bully pulpit," for when a president raises an issue, it inevitably becomes subject to public debate. A president's power and influence may be limited, but they are also greater than those of any other American, in or out of office.
Though constrained by various other laws passed by Congress, the President's executive branch conducts most foreign policy, and his power to order and direct troops as commander-in-chief is quite significant. (The exact limits of what a President can do with the military without Congressional authorization are open to debate.)
Succession
The United States presidential line of succession is a well-defined sequence of who is to fill the Presidential office upon the death, resignation or removal from office (by impeachment and conviction) of a sitting President. The first three in the long line are:
- Vice President of the United States
- Speaker of the United States House of Representatives
- President pro tempore of the United States Senate.
The Twenty-fifth Amendment to the Constitution was written and ratified to clarify and specifically outline the process for deeming a President incapable of discharging his powers and duties, and subsequently elevating the Vice President to the role of Acting President of the United States.
List of Presidents of the United States
The President of the United States is the 
