Rupert Cornwell: Clinton's best hope may come from belated show of emotion

Politics is the cruellest business. Whatever you think about Hillary Clinton, whatever your feelings about her husband or about political dynasties in general, watching a candidate upended by a force entirely out of her control, with nowhere to run for cover, is a melancholy experience.

You may find Mrs Clinton cold. You might resent her supporters' assumption, now shattered, that the Democratic nomination was hers for the asking. But you cannot help feeling sorry for her.

Few would argue she is the best prepared of the Democratic contenders, with the best command of the issues. Few can dispute that Mr Obama has been given a virtual free pass by the media. But in this potentially transformational year for American politics, such things count for nothing when the tide of history is running in your opponent's direction when experience is the dirtiest word in the political lexicon, swamped by a primal desire for "change".

The brutal irony of the moment is that, if her campaign is to be rescued, it will not be by her plans to reform US health care, to pull out of Iraq or tackle terrorism. Salvation, if there is any, will come from incidents like Monday's when her eyes filled with tears and her voice cracked, as a woman voter asked her how the campaign was affecting her personally.

The seemingly most calculating and programmed of the candidates proved was human after all. True, US presidential history offers some crumbs of comfort. But they are few. Can a candidate still win the nomination after losses in key early contests? Yes that was proved by her husband in 1992. Bill Clinton's strong second place 16 years ago was as good as a win, given the scandals that had seemed certain to sink him. But second place for Hillary is a second defeat, placing her on a downward, not upward, trajectory.

True, Nevada's caucuses are 10 days away, followed a week later by the South Carolina primary. Most importantly, almost a month remains until 2008's super-Super Tuesday on 5 February when 22 states vote, including California and Mrs Clinton's own New York. But Nevada is suddenly looking problematic, with reports that a key Las Vegas union, in a state where organised labour is strong, is about to switch to Mr Obama. South Carolina has become doubly uncertain. The black vote, a third of the electorate, was once lined up behind her. Now it seems to be moving to the Illinois senator, a black candidate who has a real chance of winning.

Sooner or later a candidate must start winning. Otherwise fundraisers flee. The temptation to shake up her team of advisers must be strong. But that would smack of desperation.

The most comforting historical parallel may be 1984. In that year, an attractive outsider named Gary Hart caused a sensation in New Hampshire with his promises of a "new politics", and defeated Walter Mondale, like Mrs Clinton the candidate of the Democratic establishment. But Mr Mondale fought back and won, largely by highlighting the vagueness of the Hart platform. "Where's the beef?" Mr Mondale famously asked.

Could that strategy work for the Clintons now, given the fuzziness of Mr Obama's policies? Perhaps. But the compressed calendar offers little time, and Mr Obama is a much more formidable candidate than Mr Hart. And 1984, with Ronald Reagan set for re-election, was anything but a transformational year.