How powerful is the American President?

Barack Obama will find that the powers of the President of the United States (Potus) are limited in myriad ways

LAST UPDATED AT 08:34 ON Mon 10 Nov 2008

Is he the world's most powerful man?

On the face of it, yes. As chief executive of the world's only superpower, he is boss of 2.7 million employees (2 per cent of the US labour force) and commander-in-chief of the mightiest army on earth. At all times he is accompanied by the so-called 'football', a briefcase containing America's nuclear launch codes. He can negotiate treaties, pardon criminals and appoint around 4,000 senior officials (though many require the Senate's consent) including ambassadors, judges, generals and cabinet ministers.

Whence does he derive his powers?

In contrast to the ill-defined powers of the British PM, his are defined in a document: Article II of the US Constitution (signed in 1787). Yet the powers thus assigned don't sound that impressive. Scarred by memories of war with King George III, most of the 56 Founding Fathers wanted to create a weak central leader (a "foetus of monarchy"), to let Congress make the laws, and to keep most power in the hands of state and local legislatures. But they were also in thrall to the trustworthy figure of George Washington, the revolutionary general widely expected to be the first man to hold the new office. That helps explain the ambiguous nature of some of his defined powers (eg. the duty "to take care that laws be faithfully executed"), an ambiguity that over time the president has systematically exploited.

And how did the presidency develop in the early years?

Washington, elected in 1789, was conscious of his role in shaping the office ("If I may use the expression, I walk on untrodden ground"). Sensitive to public fears of an over-mighty executive, he enshrined many self-limiting customs - an egalitarian term of address ('Mr President'), cabinet meetings and term limits that only later became law. His minimal activism, and that of the next five presidents, reassured the public. Only when the seventh president - Andrew Jackson, a firm believer in a strong presidency - took on both Congress and the Supreme Court in the 1830s, were the constraints on presidential power put to serious test.

What are those constraints?

The structure of American government, it's often said, is "an invitation to struggle": power is divided between executive and legislature, while authority to interpret the Constitution rests with the Supreme Court. The president's cabinet, unlike the British PM's, cannot contain sitting members of the legislature; and Potus can never be sure of a legislative majority. The Founding Fathers wanted Congress to initiate policy, and for a century after Andrew Jackson, it largely did so, the president playing a mainly oppositional role. Only after the New Deal of Franklin Roosevelt (1933-45) did the kind of presidential programme now being prepared by Obama and McCain become institutionalised.

Is he now America's lawmaker?

He has certainly become the largest source of new legislation. And though he may not vote in Congress, if he doesn't like a bill he can veto it. His veto can only be overridden by a two-thirds majority in the Senate, which has only happened 107 times (4 per cent of attempts) in the history of the US. But then again, he too finds it hard to get his own way. Between 1953 and 1996, only 46 per cent of proposals submitted by presidents were passed into law.

How else does Congress limit him?

Although the Constitution grants him some leeway to begin a sudden, defensive war, he still in theory depends on Congress to do so (see 'Vietnam', below). Congress's real power over the White House, however, lies in its control of the purse strings - "the most complete and effectual weapon with which any constitution can arm the immediate representatives of the people", as 'father' of the Constitution James Madison put it. And so it has often proved. In the mid-1990s, the federal government shut down for 28 days when the Republican-controlled Congress refused to approve Bill Clinton's budget.

And what about impeachment?

The House of Representatives, by a simple majority, can vote to impeach a president (ie. subject him to trial by the Senate) for "Treason, Bribery, or other high Crimes and Misdemeanours". But though three have faced impeachment proceedings - Clinton, Nixon and Andrew Johnson - none has been sacked. Nixon resigned before the House could vote; Clinton survived his trial. Johnson, who succeeded Abraham Lincoln after his assassination, was dubbed 'King Andy' for his resistance to Congress. In 1866, for instance, he vetoed the Civil Rights Bill giving freedom to the slaves. Desperately unpopular (Congress overrode his vetoes 15 times) he survived impeachment by a single vote.

Is the Supreme Court easier for presidents to control?

The president's power to nominate judges gives him scope to shape the politics of the court. But it doesn't always work out that way. The Senate can reject appointments; and in any case, once installed, judges are hard to control. George Bush Snr's appointment, David Souter, ended up being one of four justices to side against his son in the Florida recount of 2000.

How do they get anything done?

By ignoring the rules: most great presidents have become so while acting outside their authority. Jefferson carried out the Louisiana Purchase (buying the land of 15 states from Napoleon) despite having no constitutional right to spend $23m. Lincoln suspended the right of habeas corpus during the American civil war. In the 20th century, President Theodore Roosevelt pioneered the use of Executive Orders, presidential decrees that have the force of law. They have since been used to desegregate the US Army (Truman), ban the use of federal funds for abortion (Reagan) and start an air war in Kosovo (Clinton). As Paul Begala, one of Clinton's advisers, said: "Stroke of the pen. Law of the land. Kinda cool."

Vietnam, Iraq and the White House

"Congress shall have power to... declare War," reads Article I, section 8 of the Constitution. And so it has done five times in US history. That just leaves about 120 other occasions when the president has sent US troops into battle. Like the UK, America has largely stopped declaring its wars. The president instead asks for an "authorisation of force" from Congress, as in the case of the Vietnam war - in which 58,000 Americans and up to four million Vietnamese died; or in the case of the Korean war, no authorisation at all. After the Vietnam war, Congress tried to re-assert its authority with the War Powers Resolution of 1973, which would force the president to consult Congress and regularly seek re-authorisation for an ongoing conflict. But every president since Richard Nixon (who tried to veto it) has ignored it. The White House is still fighting the war in Iraq under an authorisation to remove (the long dead) Saddam Hussein. But now, two former secretaries of state, James Baker and Warren Christopher, are proposing a new law which would oblige the president to consult a special congressional committee before any "significant armed conflict", and to get congressional approval for any operation lasting longer than 30 days. · 

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