Hillary Clinton’s campaign claimed to have received “an historic outpouring of support” which, it predicted, would help to raise $10 million (£5 million) in the 24 hours after winning the Pennsylvania primary.

Mrs Clinton got $3 million by breakfast from 60,000 donors after she told her cheering supporters in Philadelphia that “we can only keep winning if we can keep competing — the future of this campaign is in your hands”.

Her website has replaced its usual homepage with a direct solicitation for cash as she seeks to replicate Barack Obama’s success in generating unprecedented sums from small online donors. “Keep the momentum going!” it says, “contribute $5 below”.

Mr Obama spent more than $11 million buying 10,000 television advertising slots in Pennsylvania — but still lost the primary by a wide margin.

His spending in the past month was more than any Democratic candidate lavished on all their TV advertising in the entirety of the 2004 nomination race. The strategy appears to have been to bankrupt his rival while doing his best to keep her margin of victory tight. In both respects, he failed — but Mrs Clinton probably wishes she had his problems.

According to March figures released this week, Mr Obama had $43 million cash for the remaining nine contests and only $660,000 in debts. Mrs Clinton had debts of $10.3 million and only $9.5 million available to cover them, leaving a shortfall of $800,000. This vast financial disparity must eventually work to Mr Obama’s advantage, but for the moment it is being used as stick with which to beat him.

In her victory speech on Tuesday Mrs Clinton highlighted how she had been outspent by a margin of almost three to one. “He broke every spending record in this state trying to knock us out,” she said. “Well, the people of Pennsylvania had other ideas.”

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