ANALYSIS: Hillary is confronting in Obama a gifted, attractive and skilful politician who has out-organised and out-manoeuvred her, writes Denis Staunton.
IF Hillary Clinton defies expectations by winning Texas and Ohio next Tuesday, she will have risen from the political dead for the third time in two months and remain a contender for the Democratic nomination. She was counted out before New Hampshire and again ahead of Super Tuesday, when polls predicted huge losses in key states including California, Massachusetts and New Jersey.
Clinton won all of those states, slowing Barack Obama's march towards the nomination, but 11 consecutive victories in February have more than restored the momentum behind his campaign.
Obama and his supporters are buoyant to the point of cockiness ahead of next week's primaries, while the Clinton campaign has become a gloomy nest of mutual recriminations and mounting anxiety.
Even if Clinton wins next week, she is unlikely to make a significant dent in Obama's lead among the delegates who will choose the Democratic nominee at a convention in Denver next August. Her advisers hope that, by staying in the race at least until Pennsylvania votes on April 22nd, Clinton will buy enough time for voters and super-delegates (795 party notables who account for a fifth of the votes at the convention) to experience buyer's remorse about Obama.
If she comes close to matching Obama in pledged delegates by the time Puerto Rico holds the last primary on June 7th, Clinton believes she can persuade the super-delegates to decide the race in her favour.
It's a long shot and many of Clinton's supporters are asking themselves how a campaign that once seemed invincible and a candidate who looked unbeatable a few months ago, now find themselves depending on such an unlikely scenario for success.
When Clinton formally launched her campaign just over a year ago, she did so in an internet appearance that promised "a conversation" with the American people about the issues that mattered to them. Moments after the webcast ended, Clinton's fundraisers were having a different kind of conversation with hundreds of top donors.
"Isn't it exciting?" they would say. "If you want to be the first to help make history, I can take your credit card details now for the maximum of $2,300 for the primary and $2,300 for the general. And I can take the same from your wife."
Throughout most of last year, Clinton enjoyed a huge national poll lead and was far ahead of her rivals in all the early voting states except Iowa. During debates, she remained above the fray, the clear frontrunner with an unrivalled grasp of policy detail.
The first public sign that something could go wrong for Clinton came with a fundraising report from the first quarter of 2007 that showed Obama raising more money from a much broader base of donors. Because most of Obama's contributors gave less than $100, he could go back to them again and again and ask for more - a crucial advantage as the race stretched beyond Super Tuesday.
Obama was drawing unprecedented crowds across the country and building networks of volunteers across the early voting states, but until Iowa voted, the Clinton campaign doubted that he could turn that enthusiasm into electoral achievements.
Obama won Iowa because he was better organised than Clinton, and his supporters were more enthusiastic than hers. That victory triggered a national response, notably among African-Americans, many of whom had doubted until then that white voters would back Obama.
Clinton's victories in New Hampshire and Nevada halted Obama's rise, but his thumping win in South Carolina shifted the momentum back in his favour ahead of Super Tuesday.
Meanwhile, former president Bill Clinton was playing a more prominent role in his wife's campaign, not just as an adviser but as the campaign's attack dog, jibing Obama in ways some blacks saw as racially insensitive.
The former president's clumsy remarks may have damaged his wife's campaign less, however, than his simple presence did by reminding voters a victory for Hillary would bring both Clintons back to the White House.
Bill Clinton remains popular among Democrats, but the more voters saw him, the more they yearned for a break from the two families that have dominated American politics for two decades. Obama picked up on this appetite for change, declaring that Americans didn't want to revisit the battles of the 1990s with "the same old folks".
Few Americans know much about Obama's policies and even his own supporters have difficulty naming any of his legislative achievements, but voters think of him as honest and likeable. He has an easy manner, seems comfortable in his own skin and unlike most politicians, talks and jokes the way people do in real life.
Democrats like and admire Clinton, but she has inherited some of her husband's air of shiftiness, hedging on policy and appearing secretive by delaying the release of her tax returns and White House records . Her vote for the Iraq war has dogged her campaign and allowed Obama to question her judgment.
Clinton's supporters complain with some justification that the press has given Obama an easy ride, while she is still treated mercilessly as the frontrunner, despite being the underdog. They point to misogyny in some coverage and argue commentators show open sexism towards her, while the hint of racial stereotyping about Obama would touch off a firestorm of outrage.
All of this is true but Clinton's greatest misfortune may be that she is confronting in Obama an unusually gifted, attractive and skilful politician who has out-organised and out-manoeuvred her at almost every turn.
Clinton may also be a victim of changes in the Democratic electorate that have been evident at least since 2004, but have accelerated during this campaign.
Younger, more educated and more affluent voters are playing an increasingly important role in Democratic politics, as older, white, working-class voters recede in importance.
If Obama wins this year, it will be because he has allied African-American voters for the first time with an expanding coalition of liberals, college graduates and voters earning more than $100,000 a year. It may also be that, after 20 years of Bushes and Clintons and seven years of war and the politics of fear, the people really believe the US needs most what Obama is promising - hope and change.
Denis Staunton is Washington Correspondent.