Not since John Kennedy burst on to the scene in 1960 has the election of a young and charismatic US president filled so many people with so much hope. It is a cliché, but by no means an over-statement, that the eyes of the world are on Barack Obama.

The nature of politics, however, means that Senator Obama will never be more popular than he is now, presenting as he does a new vitality and refreshing change from a discredited Republican regime whose eight years at the White House have been coloured by a collapsing economy, an unpopular war in Iraq and considerable damage to America’s reputation as self-appointed leader of the free world.

The election result can, for once, accurately be called a people’s victory since the Obama campaign was financed largely through small contributions from millions of ordinary Americans who were persuaded to part with a few dollars here and there because they were invigorated by the prospect of change. It was inevitable that both sides in the election would claim for their own the mythical Joe the plumber, but there can be no doubt now which side Main Street America has backed – and it is not John McCain.

The size of Barack Obama’s victory, a landslide, puts paid to any lingering doubts about the willingness of the American people to elect a black president. Right up until the first results began to come in there were those who wondered whether, when cossetted in the privacy of the polling booth, a significant number of potential Obama supporters might subliminally be affected by matters of race and vote instead for McCain.

But that did not happen and now that the glass ceiling has been broken, anything is possible and a journey that began 400 years ago when African slaves first arrived in North America, passed through the bloody slaughter of Civil War and then on to the 1960s, when discrimination in some southern states resembled apartheid in South Africa, is drawing to a conclusion.

Free at last, as Martin Luther King said, and it was of course to Dr King that Senator Obama turned in his acceptance speech, reminding America of a truth held to be self-evident, that all men are born free.

The cadences rang out and will continue to do so as we await the most eagerly anticipated inaugural speech since Kennedy’s, but it is already clear that the president-elect and his team must manage expectations about what can and cannot be achieved. Senator Obama referred to the “enormity” of the job ahead, and for once that word was being used in its true sense.

The scale and seriousness of the task facing the incoming American government is huge, both in terms of addressing the gravest economic crisis since the 1930s and in leading the way in the ongoing fight against terrorism.

Most incoming administrations in democracies blame the actions of their predecessors upon taking office and complain about inheriting a mess, but in this case Senator Obama finds himself facing the least promising circumstances since Franklin Delano Roosevelt was elected at the height of the Great Depression.

Not only must he repair the damage done by the credit crunch, which began in America when greedy banks were allowed to get away with offering mortgages to borrowers who were never likely to be able to repay their loans, he must also find a way of repairing the reputational damage to the United States arising from the presidency of George W Bush.

It will be a tricky task for the new president to break it gently to his fellow countrymen that America is not universally regarded as a white knight by the rest of the world, but rather as an over-bearing and trigger-happy nation intent upon interfering in the affairs of other countries. That may be some distance from the truth as far as real America is concerned, but it is undoubtedly a widely-held perception that President Obama will have to address.

He must also lead from the front in showing how America, the only real super-power, can act constructively to help shape the growth of India and China, working from the basis that the importance and spending power of these huge countries can only grow over the next decade or so.

In the case of China, a process of rapprochement with the communist government, which began under Nixon, must be strengthened and approached rather more enthusiastically than has been the case recently.

Every American president must be a statesman from day one, such are the expectations attached to the office.

To borrow a phrase from President Kennedy, the new incumbent of the White House must show that the torch really has passed to a new generation.