Bill Clinton is speaking rapidly, a sense of urgency in his hoarse voice, finger jabbing the air, as he implores this Ohio crowd to believe that his wife is the “best change-maker I've ever seen in my entire life”.

The former President, who in 1992 campaigned here as the fresh-faced 45-year-old man from Hope, turned his attention to this year's 46-year-old man of hope, Barack Obama, who on Monday packed an 11,000-strong crowd in Wright State University.

“The case Hillary's opponent is making is that you should vote for him because he embodies change - that anybody who was part of those fights in the 1990s should be disabled and disqualified to be president. Words do matter - the eloquence matters - but Hillary's worked to change people's lives all her adult life.”

The Stebbins High School gym is only three-quarters full. It was never meant to be like this. The Democratic Party's greatest rock star, 61, talking about the achievements of the past, his hair an electric white, and failing to fill a small arena in the state where his primary victory in 1992 clinched the presidential nomination for him. Before Obamamania, in the heady days last year when Mrs Clinton looked inevitable, it was her husband who was expected to be the campaigner dazzling huge crowds and raising record sums of money.

A race like a crackpot Dynasty

The contest between Barack Obama and Hillary Clinton matches any fiction

Multimedia

• Full coverage: US elections

• Pictures: race for presidency

Background

• The ascent of Barack Obama, Mr Charisma

• Decay, jobs and guns fall under the spotlight

• Free trade: Clinton/Obama's mistakes

Related Links

• Clinton 'superdelegate' switches to back Obama

• Flying in the face of defeat

The former President is working tirelessly to save his wife's imperilled campaign ahead of Tuesday's make-or-break contests in Ohio and Texas. He held five events in Ohio yesterday, and will speak at seven in Texas on Monday.

He and Mrs Clinton's top aides have said that if she fails to win both states, her White House hopes are almost certainly finished. New polls yesterday showed Mr Obama slightly ahead in Texas and having pulled into a statistical tie in Ohio. Mrs Clinton raised an extraordinary $35 million ($17.5 million) in February, only to hear that her rival has raised at least $50 million.

Yet there is a powerful sense that Mr Clinton is not just fighting for her, or even for his own legacy, but against a galling sense of injustice that his status in the Democratic Party as its swaggering baby-boom hero is being rapidly eclipsed by an untested arriviste 15 years his junior. One of Mr Obama's central arguments has been that the Clintons are part of the problem, central characters in the villainous partisanship of the 1990s, figures from the past against his promise of a new, less divisive future.

“When Bill Clinton came through here in 1992, he was exciting,” said Martin Gottlieb, who has been reporting on Dayton politics for a generation. “But nothing in my 24 years has even come close to this Obama phenomenon. He's getting crowds much bigger than Bill ever did.” Then he looked around the Stebbins school crowd. “And now look. He can't even fill a gym. If you had told me that a few weeks ago I would have been surprised.”

Mr Clinton is also facing allegations that he carries significant blame for his wife's troubles. Some Democrats say that he effectively hijacked the campaign in January. In his efforts to push back against Mr Obama - particularly in heavily African-American South Carolina - he stands accused of using race to demonise the Illinois senator, a charge he fiercely denies.

Yet one of the undeniable tragedies of this campaign for Mr Clinton has been his loss of support among the black community. His tactics in January, his detractors say, showed an indulgent loss of control that turned his wife's campaign into a co-presidential bid - bringing with it unpleasant reminders of the more vaudevillian aspects of their White House years.

The Clintons can never be written off. Mrs Clinton's February fundraising has allowed her to compete aggressively on the air against Mr Obama in Ohio and Texas. Her husband is now relentlessly disciplined in his message, and is still one of the greatest speakers and political strategists in America. Aides say that he is dismayed by the strategic blunders his wife's campaign has made, and the way money was wasted. He now has much greater control over strategy, and in Maggie Williams, Mrs Clinton's new campaign manager, a team he has faith in.

What has frustrated Mr Clinton the most, his aides say, is what he believes has been the “free pass” the media has given Mr Obama. One adviser said such soft-glove treatment is indisputable. “It's like global warming. The evidence is overwhelming,” they said.

Times Recommends

• Obama: the world can expect better of America
• Gulp! Mystery killer threatens French oyster
• Secret of Northn Lights key to space safety