The president of the United States functions in many capacities: head of state, head of government, commander in chief of the armed forces, and leader of the president's political party. The president is thus the most unifying force in a political system in which power is highly dispersed, both within the government and between the government and the people.

The President As Head of State
The president's unifying influence is exerted through the position of head of state. Like traditional European monarchs, the president is the ceremonial head of the government. The president receives representatives of other governments and performs ceremonial duties such as holding state dinners and bestowing the Medal of Honor.

Activities as head of state are not limited to the White House and Washington, D.C. The president is expected to travel within the country occasionally, a practice begun by George Washington, who undertook several grand tours to make the presidency visible to the people. Today presidents also travel extensively abroad and appear before the people of many countries. As head of state, the president symbolizes the sovereignty and power of the United States; presidential words and acts radiate an aura of significance that no other American can command.

The President As Head of Government
The president is also head of the government, ruling as well as reigning. As head of government the president is chief executive, chief diplomat, commander in chief, and chief policymaker.

Chief Executive. As chief executive, the president appoints the heads of the government departments (who constitute the cabinet) and the heads of agencies, subject to the Senate's approval, and supervises the work of the executive branch. The president's administrative role, however, is also sharply limited. The Senate may withhold approval of presidential nominees, as it did with John Tower, President George Bush's choice for secretary of defense. Despite a large White House staff, the president has difficulty keeping abreast of all activities of the vast executive branch. The bureaus, encouraged by interest groups and congressional committees, often resist and delay the fulfillment of the president's orders. Presidential power to remove personnel is circumscribed by Supreme Court decisions, and civil-service laws protect the tenure of most federal employees.

The president provides leadership in legislation. More than anyone, the president establishes the agenda for Congress. If major problems arise that require remedies, Congress and the public expect the president to offer recommendations.

The heart of the president's legislative program is conveyed in messages to Congress each January, beginning with the State of the Union address - a general, wide-ranging treatment of national problems and policies. The Economic Report follows, accompanied by the massive, detailed budget document itself; this contains the financial work plans for reaching the president's previously announced general objectives.

Subsequently, the president sends special messages to Congress, each devoted to a single topic such as foreign aid, welfare, or agriculture. Accompanying or soon following the special messages are drafts of legislation that the president urges Congress to pass. The president and the various cabinet secretaries work to persuade Congress to enact as much of the proposed legislation as possible. Increasingly, presidents, to succeed in Congress, must build coalitions of interest groups to support their measures.

The president can also be a constraining force on Congress. Recent presidents have tried to curb congressional spending. Congress and the presidency, particularly when controlled by opposing parties, may disagree regarding their priorities. The Republican presidents Richard Nixon and Gerald Ford supported more spending for military and space programs and vetoed social programs, while Congress, controlled by Democrats, attempted to reverse these priorities. Republican President Ronald Reagan induced Congress during his first term to approve substantial cuts in social programs; although the Senate was then Republican, the House was Democratic - and swayed by Reagan's great popularity. In a rare display of bipartisan unanimity in 1997, however, a Democratic president, Bill Clinton, and a Republican-controlled Congress reached an accord on federal spending levels designed to achieve a balanced budget by the year 2002 (in fact, budget surpluses began well before that.) However, that same Congress impeached Clinton in 1998 (though he was acquitted by the Senate).

Recent presidents have frequently used the constitutional power to veto. In 1975, for example, President Ford vetoed 18 bills; Congress attempted to override him 9 times and succeeded 3 times. The mere threat to veto, as repeatedly demonstrated by President Bush, may enable the president to shape legislation to his liking. Overriding is difficult because it requires a two-thirds vote against the president in each house. When their vetoes failed, Presidents Nixon and Ford in some instances impounded funds - that is, they refused to spend what Congress had appropriated. This practice was curtailed by the Budget and Impoundment Control Act of 1974. Legislation governing a "line-item" veto went into effect in 1997, and President Clinton became the first U.S. chief executive to exercise the power to veto selected parts of broad legislation already passed by Congress. In 1998, however, the Supreme Court declared the line-item veto law unconstitutional, ruling that it violated the separation of powers.

Chief Diplomat. The president is the nation's chief diplomat. "I make American foreign policy," Harry Truman once said, and Thomas Jefferson observed that the conduct of foreign affairs is "executive altogether." Success in waging major wars such as the two world wars has enlarged the presidency's prestige and power. The unpopularity of the Vietnam War, however, an undeclared war, caused Congress to adopt the War Powers Act (1973), which bars wars longer than 60 or 90 days without congressional approval. Presidents have consistently challenged the constitutionality of the act, although President Bush, before beginning the Persian Gulf War, secured congressional approval, mainly to impress Iraq with U.S. unity.

As chief diplomat, the president deals directly with the heads of foreign governments. Summit meetings with leaders of the Group of Seven major industrialized nations, for example, have become a regular event for recent presidents. Presidents preside over the negotiation of major treaties with other countries, such as the Panama Canal Treaty of 1977-78 or the Nuclear Test-Ban Treaty of 1963. They oversee arms control negotiations and work to check the spread of nuclear arms capability to other nations.

Commander in Chief. As commander in chief of the armed forces, the president is responsible for the nation's security. The president deploys troops abroad and sometimes orders them into combat to protect the interests, property, and lives of U.S. citizens. Presidents have also used the armed forces within the United States to maintain the peace, and they are empowered to impose martial law, as Abraham Lincoln did in the Civil War. The president is custodian of the country's nuclear weapons; under law the president is the only person who can order their use, and the "Black Box" through which that order can be sent accompanies the president at all times.

As a civilian commander in chief, the president embodies the principle of civilian supremacy over the military. A dramatic exercise of this power occurred in 1951, when President Harry Truman dismissed General of the Army Douglas MacArthur for insubordination. The president appoints the Joint Chiefs of Staff and other military commanders, oversees the military budget, and passes on the development of new weapons systems. The president also directs the country's participation in military alliances.

The powers of the chief executive may extend even further in time of war. The president may find it necessary to establish wide-ranging controls on the economy, as in World War II. A president may even interfere with civil liberties, as Franklin D. Roosevelt did in approving the forced relocation of thousands of Japanese Americans on the Pacific coast in World War II.

Policymaker. The president is the single most potent policymaker in economic and social affairs. Recent presidents have been concerned with such problems as health, welfare, crime, energy, inflation, unemployment, the U.S. balance of payments, the strength of the dollar abroad, and federal budget deficits. The sweeping income-tax reform legislation that President Reagan signed in 1986 represented one of his major policy objectives. The president and advisors also establish and administer national policies, within statutory limits, in such areas as social security, education, and other social issues. Presidents John F. Kennedy and Lyndon B. Johnson gave encouragement to the civil rights movement. Johnson's Great Society included programs of health care for the poor and elderly, large-scale aid to education, a War on Poverty, beautification of highways, and reduction of air and water pollution. The Reagan administration moved to cut spending on most social programs, in the belief that they were too expensive, inflationary, and wasteful. President Bush hoped, vainly, that a lagging economy would revive and help reduce the deficit and underwrite social policies. Favored by an improved economy, President Clinton attempted a major reform of health-care delivery. After the failure of this effort, however, his administration became very cautious on social policy.