Bill, the super-surrogate
There were still four hours to go before Bill Clinton was to speak at the University of California and already the queue for seats stretched around the auditorium and on to a neighbouring football field.
As the hour neared, and Mr Clinton prepared to stump for his wife's presidential bid, a warm-up speaker was dispatched on stage to get the 7,800-strong crowd buzzing.
'We want Hillary,' he tried to get the crowd to chant. 'Bill, Bill, Bill,' they shouted back.
Outside, some of the 3,500 people who had been turned away through lack of seats waved placards that made it clear that when it comes to voting, it's not just Hillary they're hoping to return to the White House. 'Vote Billary', said the signs, meshing two Clintons into one.
For a man who once described his own presidency as a 'two for one', on account of his wife's political input, and declared 'we'll be back' as he handed over power to George W. Bush in January 2001 after eight colourful years in office, Mr Clinton makes no secret of his enthusiasm for resuming life at 1600 Pennsylvania Avenue.
But in supporting his wife's presidential campaign, 16 years after she campaigned for his, he has found himself walking a tightrope on which he must balance two powerful roles; on one hand as a sentimental husband praising his wife's human qualities and on the other a snarling attack dog rushing to her defence with teeth bared.
The risk of getting the balance wrong, say strategists, is that in wanting to become the world's most powerful woman, Senator Clinton could appear weak by unleashing her husband - once arguably the world's most powerful man - as her defender-in-chief.
'The image of her as Bill Clinton's wife and a former first lady will always be activated every time people hear her name,' says Elizabeth Ossoff, a psychology professor at Saint Anselm College in Manchester, New Hampshire, specialising in politics.
'When Bill Clinton speaks, he does so as the former president of the United States, even though he says he's only there as Hillary's husband,' Professor Ossoff said.
'The handicap is his position as former president overshadowing her position as the candidate. There will be people who think that if she's president, will it really be her or will he be pulling the strings in the background?'
Drawing on goodwill gained during his 1993 to 2000 tenure as the 42nd US president - when he oversaw the longest period of peace-time economic expansion in America's history, and left office with a 65 per cent approval rating despite having been impeached for lying over his affair with the intern Monica Lewinsky - Mr Clinton has received a rock-star welcome from supporters on the campaign trail.
'Bill Clinton speaks; woman faints,' one newspaper headline in Las Vegas exclaimed. 'Bill Clinton dazzles friendly Napa crowd', gushed another in California, quoting a joyous 28-year-old still swooning over the fact that he had shaken her hand.
'He's the closest thing to a Kennedy that my generation has,' Juliet Christian-Smith told The Press Democrat, while one political correspondent following him around New Hampshire noted that 'some women confessed their love for Bill Clinton the way they talk about chocolate'.
Yet the Clinton campaign has not been all charm offensive, folksy glad-handing and reminiscing over sunnier times. Feeling the heat from Senator Barack Obama, a fellow contender for the Democratic nomination who crushed Senator Clinton at this month's Iowa Caucus Mr Clinton has also torn off the leash in agitation and anger.
In a red-faced rant to students in New Hampshire, he accused Senator Obama of having spun the public 'the biggest fairy tale I've ever seen' by claiming to have been the only Democratic candidate to have opposed the war in Iraq consistently. He later apologised.
Elsewhere, he asserted that Senator Obama's campaign had branded his wife a racist. In a previous attack, he had railed provocatively that a vote for Senator Obama would be akin to 'rolling the dice' on America's future.
On Thurday, he indulged in a testy exchange with a reporter in Nevada over suggestions that his wife's campaign had engineered legal action by unions that could block Senator Obama's voters from getting to the polls in Las Vegas.
'Once again, the former president has been deployed as the Clinton campaign's heavy artillery,' notes political blogger Marc Cooper. 'Smoother talking than a slick diplomat, more charming than a movie star, equal parts statesman, wonk (studious, hard-working person), lounge comic and attack dog, Bill Clinton is nothing less than Hillary Clinton's super-surrogate.'
In recent days, both Clintons have become embroiled in a new race row with the Obama campaign after she seemed to downplay Martin Luther King's role in realising civil rights in America by noting that it had taken Lyndon Johnson to finish the job by signing those rights into law while he was president.
The controversy has played directly to the benefit of Senator Obama. South Carolina's most influential black politician, US House Majority Whip James Clyburn, said he was so upset by Senator Clinton's remark - and her husband's perceived ridicule of Senator Obama - that he was reconsidering his endorsement of her candidacy.
Mr Clinton, often bestowed during his White House years with the honorary title of 'America's first black president' for his empathy with African-American issues, was wheeled out to make amends.
'He's tried to step out there and take some of the heat so that she doesn't have to,' Professor Ossoff said.
'You never want your candidate to be the one to throw the stone at the other candidate - especially in the primaries, because you are throwing a stone at one of your own. But he also has to watch his own image, as to how much he can do that without it reflecting negatively on her and consequently back on him.'
Aides have described Mr Clinton as having a Vesuvian temper that will erupt fiercely, in contrast to his wife's more slow-burning style.
His tendency to outbursts, some fear, risks causing a distraction and is said to have caused concern within the campaign that he could expand from attack dog to an off-course missile.
Senator Clinton's tears during a question-and-answer session in New Hampshire are widely perceived to have softened public image of her as a hard-nosed 'Ice Queen'. Now Mr Clinton's most comfortable niche, Professor Ossoff suggested, would be in softening his own role and building on that momentum to 'help people understand who Hillary is as a person'.
'Everyone knows she's a policy wonk, she can do the talk - now let them see who she is as an individual,' she said. 'I think the campaign isn't going to want to send him out to be the primary attacker. They are going to look for other prominent Democrats associated with the campaign to do that and let him present more of the 'Let me tell you who Hillary really is' stuff. He's important in helping people understand who she is as a person.'
For some voters, however, it is not Senator Clinton who matters.
A study of exit polls during the Democratic primary in New Hampshire last week showed that a significant number of her voters were actually more dazzled by her husband's glow.
If Mr Clinton had been on the ballot, too, they were asked, would you have voted for him or for her? - 58 per cent answered that they preferred him over his wife.
'This is not a compliment to Hillary,' said Larry Sabato, professor of politics at the University of Virginia.
'It's obvious that without Bill, she would not be in a position to win the party nomination.'
But asked at a rally in California what role he would play in a Hillary Clinton administration, the former president made it clear who would be wearing the trousers.
'Whatever I'm asked to do,' he replied meekly.