"Together, we can make history" was the last line of the speech Hillary Clinton delivered to 3,000 people at Sioux Falls fairground in South Dakota on Monday night. She meant, of course, that they would make history by electing the first woman president of America.

But history of another sort was playing out before us. It would turn out to be the last joint campaign appearance of what until now has been called the First Family of the Democratic Party.

Mrs Clinton's husband Bill, who was with her on stage with their daughter Chelsea, inadvertently admitted as much at an earlier event. "This may be the last day I'm ever involved in a campaign of this kind," he mused.

Last night, less than 24 hours later, the Clinton family were gritting their teeth as Barack Obama crossed the delegate finishing line.

The psychology change was profound. On Monday night, Mrs Clinton was all fight. She was on course to amass more popular votes than Barack Obama – a problematic claim for some time now – and she, not Mr Obama, would be the better opponent to the Republican nominee John McCain. "The campaign isn't an end in itself," she told the crowd in a hangar-like fairground building. "It's to nominate the strongest candidate to go against John McCain."

But the family tableau was poignant, almost touching. The cohesion of a family in an honourable quest on display for one last time. Bill was doing his old lower-lip biting thing. Mid-way through her speech, Hillary, as earlier in the day, had to relinquish the microphone to Chelsea because of a dying voice. Bill held on to the stage railings. He was looking at Hillary with a question: "Are you going to make it? Are you OK?" She was nodding, sipping water and swallowing throat lozenges. Chelsea spoke fluently and her parents' pride was clear on their faces.

Mrs Clinton had come this far, but on the very last lap her body was giving in. It was that adrenalin thing. You can run on it for months but, when the end so much as pops into view, that urgent rush begins to drain away and the ailments kick in.

The audience knew what they were watching, too. They had come to the fairground well aware that Mrs Clinton's chances of becoming the Democratic nominee were almost nil, whatever the result in their state. "I'm here because I like her, because she was my first choice," said supporter Jan Haar, 51.

Bill looked like a raspberry ready to burst. The loyal husband, some people will argue, more than anyone sabotaged his wife's chances by airing too many outspoken opinions along the way. Yesterday, back in her Chappaqua home for the first time in 15 months, Hillary's task was not to plead for votes. It was to think. The reckoning for the former First Lady was upon her. The race was over and it was Barack Obama, not her, who had the finishing tape at his belly.

Hillary has been beaten. Bill has dishonoured himself. And Chelsea? Chelsea need have no regrets. She may be the candidate that brings the family back to the campaign trail again. But that drama is for another decade.

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