Barack Obama trounced Hillary Clinton, his rival for the Democratic presidential nomination, in contests across America last night, beating her by margins of more than two to one in Washington state and Nebraska and winning the Louisiana primary by 53 per cent to 39 per cent, with over two-thirds of the votes counted.

The scale of his triumph sent shockwaves through Clinton’s campaign, even though it was braced for a poor night. Obama won the Nebraska caucuses by 68 to 32 per cent and Washington state by 68 to 31 per cent. He won 90 per cent of the vote in the US Virgin Islands.

The Illinois senator, 46, who hopes to become the first African-American president of the United States, said “There is no doubt that she has not generated the kind of grassroots enthusiasm that we have.”

Obama’s clean sweep will help him to catch up with Clinton in the race to obtain the 2025 delegates needed to secure his party’s nomination. He now heads into the delegate-rich “Potomac” primary in Maryland, Virginia and Washington DC on Tuesday with vital momentum.

Obama greeted the results at Democratic party dinner in Richmond, Virginia, last night, which was also attended by Clinton. She left the stage to chants of “Obama” before the arrival of her opponent.

“I knew I wouldn’t be Washington’s favourite candidate. I knew we wouldn’t get all the big donors or endorsements right off the bat. I knew I would be the underdog,” Obama said, referring to the start of his campaign a year ago. “But then something started happening.”

Last night’s victories give Obama an edge in the most evenly matched Democratic presidential race in generations, proving that he can beat Clinton in organisation, fundraising and the popular vote. The New York senator was forced to loan her own campaign $5m last month to stay competitive with Obama, despite raising over $100m last year.

Clinton’s camp admitted that it was “dramatically outspent” by Obama in last night’s contests, an excuse it never imagined it would have to make when the battle for the nomination began.

The breadth of Obama’s success from the West Coast to the South and the white heartlands of Middle America will boost his claim to be the best placed candidate to beat John McCain, the near-certain Republican nominee.

Obama is expected to win a string of victories in the next few weeks before Clinton has a chance to stop his momentum in Texas and Ohio on March 4, where she is counting on her strength among Hispanics and blue-collar workers to revive her fortunes. But if her campaign remains starved of wins, he may be able to chip away at her support.

The exit polls in Louisiana showed the Democratic race remains polarised between race, gender and class in some states, with Obama winning 82 per cent of the black vote and Clinton winning 70 per cent of the white vote, according to CNN. He continued to attract well-educated voters of all races, while she scored well among blue-collar workers.

Clinton is hoping for a consolation victory when Maine holds its caucus today, but the fervour and commitment of his supporters could outmatch hers.

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