Hillary Clinton pulled off yet another unpredicted comeback with her three primary victories this week, increasing the likelihood that the race will go all the way to the final contest in Puerto Rico, and beyond
In the drawing room of Hillary Clinton's handsome Georgian house off Washington's Embassy Row, half the guests were muttering about media bias and treacherous congressmen while the rest were gazing out at the empty swimming pool in shocked silence.
It was the middle of February and, the previous day, Clinton had suffered thumping defeats in Maryland, Virginia and the District of Columbia, bringing home to these Washington insiders for the first time how powerful Barack Obama's momentum had become.
One of Clinton's staffers recited to me a litany of betrayal, starting with the Irish-American congressman who had phoned Clinton to tell her he was supporting her, only to endorse Obama three days later.
Walking his dog the previous weekend, the staffer had passed the house of an old friend who had received a political appointment when Bill Clinton was president and only a few weeks ago, asked Hillary to help him win an extension of his contract.
"Here was a guy who owed everything he had to the Clintons and right there in front of his house was an Obama yard sign," the staffer said.
Just as the mood of the party threatened to dip into irreversible gloom, Bill Clinton arrived with a message that was at once optimistic and stark. Hillary could still win, he said, but only if she pulled off victories in the next big states to vote - Texas and Ohio.
The campaign had enough money to fight in both states and 30,000 volunteers were pouring into Texas from Arkansas and Oklahoma to set up an effective ground operation. By this time, however, Obama had 150,000 volunteers in Texas, had won the support of some of the biggest and richest unions and was preparing to outspend Clinton two to one, running four TV ads in Ohio for each one she aired.
As Obama ran up an unbroken run of 11 victories in February, his lead among the delegates who choose the Democratic presidential nominee began to look invincible and political commentators asked why Clinton insisted on staying in a race she couldn't win.
Clinton's campaign was plagued by infighting and her chief strategist, Mark Penn, was almost universally loathed both inside and outside her Virginia headquarters. Greasy and dishevelled, Penn is singularly lacking in personal charm but he has enjoyed the confidence of both Clintons for more than a decade.
A pollster who specialises in "micro-trends" and niche targeting, Penn has insisted from the beginning that Clinton should prove herself as a tough leader capable of serving as commander in chief rather than stressing her softer, more personable side. It was also his idea to ignore the caucuses in smaller, rural states that Obama won by huge margins, helping to broaden his lead among pledged delegates.
Ignoring the caucuses proved to be one of Clinton's biggest mistakes, making it almost impossible for her to catch up with Obama among pledged delegates, so that her victory could depend on the superdelegates - 795 senior party figures - overturning the majority of delegates chosen by voters.
Just over half of the superdelegates, most of whom are members of Congress, have declared for a candidate, with about 241 backing Clinton, compared to about 202 for Obama. As Obama's run of success continued through February, however, he picked up a few dozen superdelegate endorsements, while Clinton lost five.
Faced with the prospect of her campaign's extinction if she lost Texas and Ohio, Clinton decided, in her campaign's words, to throw the "kitchen sink" at Obama, questioning his foreign policy credentials and sneering that his eloquent speeches were no substitute for the tough grind of policy making.
In Texas, she ran a TV ad showing children asleep while a phone rings at 3am in the White House, asking voters who they would prefer to answer the call. The ad showed Clinton picking up the phone, wearing a smart brown jacket, a gold necklace and thick-rimmed glasses - at 3am.
The ad was roundly condemned as fear-mongering, and Obama responded that Clinton had already failed the 3am test when she voted to authorise the Iraq war in 2002.
As she sought to undermine Obama's claim to represent a new, transcendent politics, Clinton received two lucky breaks - one from a Chicago courtroom and the other from Canadian television.
A day before Tuesday's primaries, jury selection started in the trial of Tony Rezko, a Chicago property developer and prominent Obama fundraiser accused of extortion and corrupting local politicians. Obama is not accused of any wrongdoing but he has faced questions about a 2005 land deal with Rezko's wife, which he later acknowledged was a mistake.
"It was a mistake to have been engaged with him at all in this or any other personal business dealing that would allow him, or anyone else, to believe that he had done me a favour," Obama said.
Although Obama's ties to Rezko, which go back more than 15 years, have been reported extensively in the Chicago press, this week's trial prompted the national US media to examine the relationship in detail for the first time. Obama became rattled earlier this week when a press conference was dominated by questions about Rezko, walking away from reporters after eight questions.
Clinton's second stroke of luck came when Canada's CTV network reported that Obama's top economic advisor, Austan Goolsbee, had told Canadian officials not to take too seriously the candidate's promise to renegotiate a North American trade deal.
Obama, who had put his opposition to the trade pact at the centre of his campaign in Ohio, initially denied that Goolsbee had met the Canadian official.
When the Canadians leaked a memo of the meeting at their Chicago consulate, quoting Goolsbee as describing Obama's stance on trade as "political positioning", Obama admitted that the meeting had taken place but claimed that the memo reported it inaccurately.
THE CLINTON CAMPAIGN has long complained about media bias against them and what they perceive as a free ride given to Obama. It's true that much of the commentary has been hostile to Clinton and some pundits have displayed open misogyny in talking about her.
When Clinton won New Hampshire unexpectedly, most journalists at her election night party watched the results coming in on giant screens as if they were witnessing the planes crashing into the Twin Towers on 9/11. And there was an unmistakeable note of glee in many of the premature obituaries written for her before New Hampshire, before Super Tuesday and before this week's primaries.
Part of the problem has been that throughout 2007, when Clinton looked like the inevitable Democratic nominee, her campaign treated the press with frank contempt, keeping access to a minimum and refusing almost every request for an interview. Before Iowa, only a handful of newspapers - The Irish Times was the only non-US publication - were granted a full-scale interview with Clinton. After her defeat, however, she became more accessible, even doling out peach cobbler to journalists travelling on her plane.
Clinton's complaints about media bias gained little resonance until the comedy show Saturday Night Live ran a parody of a candidates' debate that featured NBC's Tim Russert hurling impossible questions at Clinton while another moderator asked Obama if he was comfortable or if he needed another pillow.
The skit appeared to embarrass journalists into adopting a more robust approach to Obama just as his campaign, which had long been very friendly to the media, became more restrictive. A few weeks ago, barriers started to go up at Obama rallies to prevent journalists from mingling with supporters before and after the events.
It was a silly restriction that most reporters circumvented by taking off their press badges and walking into the rally as members of the public but it helped to sour relations. After his defeats on Tuesday, Obama chided reporters for swallowing Clinton's line about giving him a free ride, suggesting that it was now time to return to the old, friendly pattern.
Obama expects to win a caucus in Wyoming today and a primary in Mississippi next Tuesday, but Clinton has succeeded not only in extending the race for the nomination but also in changing its terms. Before Tuesday's primaries, Obama had lined up a few dozen superdelegate members of Congress to call on Clinton to bow out and let the party rally around Obama.
These superdelegates have now backed off, waiting to see how the next contests play out, particularly in Pennsylvania, the next big state to vote on April 22nd. Clinton has the support of Pennsylvania's governor Ed Rendell and she expects to fare well in rural parts of the state.
Obama is banking on a big African-American vote and strong support in the suburbs of Pittsburgh and Philadelphia, as well as his financial edge over Clinton, which will allow him to dominate the airwaves in advertising.
Both campaigns are looking ahead to the remaining contests, which may include re-runs of the unauthorised primaries in Michigan and Florida. Neither expects to win enough pledged delegates - those chosen in primaries and caucuses - to pass the threshold of 2,025 needed for the nomination.
That makes the hunt for superdelegate support more urgent than ever, and Clinton has dedicated 20 campaign staff solely to pursuing those who remain uncommitted. They are led by Harold Ickes, her husband's former chief of staff and a political veteran with an appetite for hard-knuckle tactics.
"We are vigorously talking to the remaining uncommitted automatic delegates. The Obama campaign is doing the same thing," says Ickes.
"The ones that we've talked to have increasing questions about some of the relationships Senator Obama has had in the past and they're increasingly beginning to question some of his past issue positions. For instance, in the late 1990s he was a fully fledged advocate in the Illinois state legislature for very strict handgun control. Apparently he has changed that position now that he is running for president."
Ickes says the Clinton campaign would continue to chip away at Obama's unanswered questions, although he denied that this was an attempt to damage the other candidate.
"We feel that Hillary has been vetted for the past 15 years. There's not another shoe in her closet to drop. It's clear that too much is yet unknown about Senator Obama. Let's take the case that's being conducted in Chicago and whatever his relationships are with Mr Rezko. I think we'd prefer to find that out before he's nominated rather than after he's nominated," he says.
Obama has signalled that he will be stepping up his attacks on Clinton, questioning her claim to foreign policy experience and asking why she has yet to release her tax returns and her White House records. The Obama campaign is planning fewer big rallies and more policy-oriented, round-table discussions in an attempt to blunt Clinton's edge as the candidate who appears better grounded in policy.
Clinton hopes that the toughness she has shown in battling her way back into the race will appeal to voters who are increasingly worried about the economy. She is also banking on the continued support of women voters, many of whom have been outraged by what they perceive as her unfair treatment by the media and the haste with which some commentators wanted to drive her out of the race.
If Obama retains his lead among pledged delegates and in the popular vote after Puerto Rico votes in the last contest on June 7th, Clinton will have great difficulty in persuading superdelegates to choose her instead. She will argue that, as the winner of most of the big states - including delegate-rich California and battleground states such as Ohio and New Jersey - she is best placed to defeat John McCain in November.
She will also claim that her supporters - women, older voters and the white working class - are those most vulnerable to the Republican candidate, whereas Obama's base of African-Americans and well-heeled liberals will vote Democratic regardless of the candidate.
Obama claims that he has shown that he can not only attract new voters into the process but appeals to independents and even to disaffected Republicans, whereas Clinton is already known to all Americans and disliked by almost half of them.
VETERAN POLITICAL ANALYST Michael Barone says that if Democrats choose Obama, they will be taking a gamble that he will excite the American public as much in November as he has during the primary campaign.
"He's got a higher upside potential than Hillary Clinton because people don't know him, because this message of emphasising what Americans have in common is a very appealing one after a long period of polarised politics, you know, where his personal qualities seem, in many ways, attractive," says Barone.
"But he's also got a lower downside potential. He's got far less experience. You know, his experience with foreign policy and defence policy is extremely limited. The chances of him saying or advocating something which would turn out to be a political liability, I think, is higher than it would be for somebody with more experience . . . So there's a lower downside potential as well as a higher upside potential. You know, Hillary Clinton was going to get at least 48 per cent of the votes and not more than 52 per cent of the votes or something like that. Barack Obama could do better than that and he could do worse than that, in my judgment."
Both campaigns expect the remaining superdelegates to make up their minds after the last primary in June but before the nominating convention in August. Everyone in the party agrees that a battle on the convention floor can only damage their candidate's chances against John McCain. But, for the moment, the superdelegates appear content to allow the primary process to take its course.
"We just think that the uncommitted superdelegates are standing back," Ickes says. "They're keeping their powder dry and they're watching this process unfold. There's another 12 states to vote, there's another 600-plus delegates to elect. There are three months to go before Puerto Rico finalises the process."