The office conjures up images of America's greatest leaders. From Washington to Lincoln, the Roosevelts and Truman.

But in recent times the Presidency has been associated with human failings, not heroism.

The threat of impeachment has loomed over two presidents in the last 30 years - the national impulse to rally round the White House has been corroded by cynicism.

All of which means the candidates for America's highest office now bear an enormous burden of responsibility. In this first election of a new century, at a time when national prosperity is high and faith in politics alarmingly low, they must prove that the democratic process still works - and still matters.

Twist in the tale

Indeed the 2000 election is not just another political battle between Republicans and Democrats. This time there's a twist, which sees both party establishments seriously challenged from within.

At issue - the role of money and party institutions in determining the choice of candidates put before the American people.

For much of Bill Clinton's Presidency - as Americans enjoyed an unprecedented economic boom - it was widely assumed that there would be no meaningful contest for the Democratic nomination.

Vice-President Al Gore was the diligent understudy being groomed to assume star-billing.

He has spent much of the last three years plotting his course to the White House, establishing a vice-like grip on the party establishment, locking up endorsements and financial support.

But somewhere, somehow, Al Gore's ambitions ran ahead of the popular mood.

Lewinsky legacy

The Lewinsky scandal left the public tired of the Clinton Administration. The vice-president has found it difficult to distance himself from his boss and even harder to convince the public that he has a coherent vision for America's future.

Which leaves him vulnerable to the challenge posed by former senator and professional basketball player, Bill Bradley.

Diffident, monotonal and seemingly immune to self-doubt, Mr Bradley has shaken up the 2000 race by calling for a campaign of big ideas and fundamental reforms.

He wants to regulate campaign finance to limit the role of money in politics and he wants politicians to pursue an ambitious agenda - universal health insurance is his grand plan. He has also by-passed the party establishment by tapping into new sources of wealth including Silicon Valley and the sports industry.

Significantly a similar "Establishment versus Insurgent" race is developing in the Republican Party.

Father's fame

The Republicans have had a front-runner in the form of Governor George W. Bush of Texas ever since this race began to take shape.

By the time he decided to formally declare his candidacy Mr Bush was streets ahead in the polls. Not least because he has a famous father with a famous name - a Presidential pedigree.

But he has other attractions for his party's leadership. In Texas he has been a hugely popular governor, with a proven appeal to women and Hispanic voters; His style is relaxed and telegenic - in short he has the aura of a winner.

And after eight years of Bill Clinton in the White House nothing matters more to Republicans than winning. That's why money has been pouring into the Bush campaign for the past year.

Around 70 million dollars at the last count - which means Mr Bush could be the first candidate to raise and spend more than 100 million dollars in American history.

But this success has also raised questions and resentments. Is this the way US presidential politics should work? Is fund-raising prowess more important than intellectual vision and personal integrity?

Democracy under threat

The embodiment of those concerns is Mr Bush's only serious Republican challenger, Senator John McCain of Arizona.

Central to the McCain bid for the presidency is the idea that campaign fund-raising is destroying American democracy.

He portrays himself as an independent-minded conservative - hardened by years in a North Vietnamese prison - prepared to fight for principle over corporate interests.

This combination of war hero and maverick has turned him into a strong contender in New Hampshire - the first primary state - but his national campaign is desperately under-resourced. As the primary season gathers pace he will struggle to keep up with the Bush machine.

And therein lies the cold reality of election 2000. Political commentators have eagerly hailed the emergence of Mr Bradley and Mr McCain as the harbingers of a new "Politics of Authenticity", but the demands of the campaign cycle still leave the odds against them.

In the six weeks after the New Hampshire primary on 1 February almost all of the key battleground states, including California, New York and Texas, make their choices.

Staying power

The candidates will need money and a well-established national organisation to remain competitive. Mr Bradley seems to have the infrastructure in place to maintain his challenge; the McCain campaign may be finished if he doesn't win in New Hampshire and then South Carolina.

So much for the machinery of politics, what of ideology? In 2000 it seems most voters are not focussing on the policy issues which define the candidates and their parties.

The economy is in good shape - rising prosperity and low unemployment have left most Americans relatively content. The country isn't locked in an international conflict which has brought foreign policy to the top of the agenda.

Contender's qualities

So it is understandable that the personal qualities of the main contenders are being closely scrutinised.

Especially in the wake of a Clinton Presidency which appears to have increased popular skepticism about the trustworthiness of politicians. But it would be wrong to conclude that the race for the White House in 2000 doesn't really matter.

There are real choices to be made about the role of the federal government in healthcare, education and gun control. Americans must decide if they want to use the budget surplus to finance deep tax cuts, strengthen the military, or shore up the social security system.

So this election represents a challenge not only to the candidates, but to the voters as well. In recent US presidential elections turn-out has fallen below 50%.

Much has been written about this apparent "disconnect" between the public and the democratic process - by the end of the year we will know whether America's body politic is in need of radical surgery.