The president of the United States is chief executive officer of the executive branch (see separation of powers), and commander in chief of the armed forces of the United States. The role of head of state is theoretically confined to that of the nation's chief representative in foreign affairs. Theoretically so, because the founding of the American republic was designed to limit powers of the chief executive's office in order to prevent too much power being controlled by the executive branch under the command of one person. This is also why the office of president is referred to in the lower case "president" as opposed to "President," unless one is speaking directly to or about a specific president or using the full name of the office of the president. For example: "President John Adams was president after George Washington, President of the United States, who served two terms as the first President of the United States." The popular acronym used to refer to the president, typically the current president, is POTUS, which stands for... you guessed it: President of the United States. The use of "President" is meant as an abbreviated version referencing the office of the president.

Eligibility and Term in Office

To serve as President of the United States you must be a citizen born in the United States, thirty-five years old, and fourteen years a resident in the country. The term of office was legally restricted to two four year terms by the Twenty-second Amendment, with an allowance for a total of ten years if by chance a Vice President were to take the oath of office in the absence or death of a president. Prior to Franklin D. Roosevelt's four terms, no president had ever served more than the two terms in office established in George Washington's second farewell address beginning the tradition.

Constitutional powers of the President

• commander in chief of the United States Army and Navy, and of the militia of the several states, when called into service of the United States.
• to veto legislation that has been approved by both houses of Congress, however, a veto may be overridden by a two-thirds majority vote in both houses of Congress - making the bill law.
• the power to grant reprieves and pardons for offenses against the United States, except in cases of impeachment.
• with the advice and consent of the Senate and two-thirds majority approval of the Senate, the president may make treaties.
• the president can appoint officers to the executive branch, other offices of the United States, the judicial branch and the Supreme Court, with the advice and consent of the Senate.
• the president may fill vacancies when the Senate is in recess. Such commissions will expire at the end of the Senate's next session.
• the president may on extraordinary occasions convene either or both houses of Congress.
• in cases of disagreement between both houses of Congress the president may adjourn both houses until such time as he shall think proper.

Constitutional requirements upon the President

• to uphold the Constitution of the United States.
• to take care that the laws be faithfully executed.
• the president shall from time to time give to the Congress information on the state of the union, and recommend to their consideration such measures as he shall judge necessary and expedient.

Other powers of the President

The President of the United States has two other very influential powers that have evolved over time. The President has a great deal of persuasive power because of one simple reason: whereas Congress and the attention it receives is distributed amongst 535 people the President is one person and receives all the attention which is focused on the executive branch. Strong personalities and leaders throughout American history have helped shape the importance of the office. Characters like Abraham Lincoln, and Franklin D. Roosevelt who led the United States through their darkest hours and reshaped the nation out of civil war and economic depression have led to other changes in the relationship between the branches of government.

Another great power of the president which has also been affected by the evolution of the republic is the executive order. With Congressional legislation and an increasingly larger federal government the executive order has grown in significance and broad effects. Times of war and changes in international relations and globalization have been significant impetuses for increasing the powers of the presidency by means of Congressional legislation. Executive orders can even be issued to expand the powers of the presidency since such power has been permitted to grow over time by Congress.