Barack Obama strolled on to the stage and raised his hands in gentle applause. He is well used to seeing an audience with mouths stretched wide open to scream, bottoms bouncing in seats and placards being shaken frantically with two clenched fists.

There is only one Democratic presidential runner who can generate such frenzy – and it is not Hillary Clinton.

Her own speech, laced with substance and carefully drawn dividing lines against the presumptive Republican nominee John McCain, had been received politely at the annual dinner for the Virginia Democratic Party in Richmond on Saturday night.

It was a rare chance to see the two candidates perform back to back. But it was the arrival of Mr Obama, fresh from his hat-trick of victories in Louisiana, Nebraska and Washington State, that turned this crowd of 5,000 into an writhing mass of noise.

In the midst of all the tumult was Tom Urban, a lawyer who had travelled down from the north of the state. He remained seated most of the time and appeared a little embarrassed by such excitement. “I really don’t buy into all this hope stuff,” he said.

So why was he wearing an Obama sticker? “It’s purely pragmatic,” he said. “I like Hillary and, if someone could name me a state which John Kerry [the Democratic nominee in 2004] lost and she would win, I would vote for her. I think that when we get to a general election Obama can win votes from Republicans and Independents in places she cannot because she is hated by the Right – she is too polarising a figure to beat McCain.”

It was a point made in more subtle fashion by Mr Obama himself in his speech, who pointed out that his victories over the past week were in traditional Republican-leaning or swing states – at least some of which the Democratic nominee must win to take the White House. “There is a reason why the last six polls in a row have shown that I’m the strongest candidate against John McCain,” he said. “It’s because we’ve done better with Independents in almost every single contest we’ve had.”

The choice now facing Democrats was “between debating John McCain about who has the most experience in Washington – or debating him about who’s most likely to change Washington – because that’s a debate we can win”. He added: “And it’s a choice between taking on John McCain with Republicans and Independents already united against us or running against him with a campaign that’s united Americans of all parties around a common purpose.” It is not so much that Mr Obama is appealing now to heads rather than hearts but that a campaign – long sustained by hope and his inspirational qualities alone – is morphing into one that can can appeal to both.

This is the problem for Mrs Clinton, which has left her fighting on two fronts. She has tried to reduce the inspiration deficit by putting greater emphasis on her potential to be the first woman president. On Saturday night she talked of the prospect of a

Democrat “placing his or her hand on the Bible to be sworn in” at the inauguration next year. And her speech claimed that this extraordinary battle with Mr Obama would ensure that future generations of children “will take it for granted that a woman or an African-American can be president”.

But Mrs Clinton’s best lines were still focused around policy and the difference she promises to deliver to the lives of ordinary citizens. She emphasised the pressing problems President Bush will leave behind including two wars, an economy in trouble and a crisis in healthcare and energy provision.

Her campaign repeatedly emphasises that Mr Obama’s health policy would not guarantee care for all the 47 million uninsured Americans. On Saturday she said: “I’m the only candidate – Democratic or Republican – left in the race who can offer a healthcare plan to cover every single man, woman and child,” she said.

Mrs Clinton does best among Democrats who believe that Mr Obama’s appeal is too soft to survive the heat of November’s general election. “If I’m the nominee you will never have to worry that I will be knocked out of the ring,” she said, “because I have the strength and experience needed to run this country and I’m ready to go toe-to-toe with Senator McCain whenever he desires.” There is a relentless-ness to her campaign which should not be underestimated. When she talked of how the battle for civil rights or women’s votes were won because people “just kept going”, Mrs Clinton could have been describing herself.

But the worry is beginning to show on the faces of her supporters. Margaret Hastings, 47, who had spent most of Saturday campaigning for Mrs Clinton outside the Siegal Centre in Richmond where the dinner was held, put it most simply. “I’m scared,” she said.

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