WASHINGTON - Hillary Clinton won a landslide victory over front-runner Barack Obama in West Virginia and vowed to keep her beleaguered White House bid alive until voting ends in the Democratic race.

Clinton hoped her crushing defeat of Obama on Tuesday would slow his march to the Democratic nomination and bolster her case that she is the Democrat with the best chance to beat Republican John McCain in November's election.

Obama, who would be the first black U.S. president, retains a nearly unassailable advantage in delegates who will select the nominee at the party convention in August. West Virginia had only 28 delegates at stake.

"This race isn't over yet. Neither of us has the total delegates it takes to win," the New York senator and former first lady told a victory celebration in Charleston, West Virginia.

"I am more determined than ever to carry on this campaign until everyone has had a chance to make their voices heard," she said, looking ahead to the final five nominating contests that conclude on June 3.

With 100 percent of the precincts reporting in West Virginia, 67 percent of voters supported Clinton while 26 percent backed Obama.

Obama made only one brief campaign stop in West Virginia before the contest and stayed far away, when he visited the general election battleground of Missouri and looked ahead to a November match-up with McCain.

"A vote for John McCain is a vote for George Bush's third term," Obama said in Cape Girardeau, Missouri. "We cannot afford any more of the Bush-McCain program."

Obama did not appear in public after the voting ended in West Virginia, but a campaign spokeswoman said he left Clinton a congratulatory message on her mobile phone. He is scheduled to make stops in the general election battleground states of Michigan on Wednesday and in Florida next week.

RACE A FACTOR

Exit polls in West Virginia showed two of every 10 white voters said race was a factor in their decision, and only a third of those said they would support Obama against McCain. Obama gained more than a quarter of the white vote in West Virginia, which has a small black population.

Less than an hour after the polls closed, Clinton, whose campaign is at least $20 million (10.3 million pounds) in debt, sent supporters text messages and e-mails, urging them to donate money to her campaign, according to The New York Times. She said her strength in big states like Ohio and Pennsylvania that are critical in a presidential election made her the best candidate against McCain.

She made a direct appeal to the remaining Democratic voters and superdelegates - party officials who can back any candidate and will help decide the nominee.

"I'm asking people to think hard about where we are in this election, about how we will win in November," she said. "I am in this race because I believe I am the strongest candidate."

A delegate count by MSNBC gives Obama 1,880 delegates to Clinton's 1,718 with six more delegates to be awarded in West Virginia. That leaves him 145 short of the 2,025 needed to clinch the nomination.

Neither candidate can win without help from superdelegates - nearly 800 party officials who are free to back any candidate. Obama has been gaining ground among superdelegates for weeks and picked up four more on Tuesday.

"Barack Obama leads in pledged delegates, contests won and superdelegates. And for perspective, while 28 pledged delegates are up for grabs this evening, Obama has won the support of 27 superdelegates in the course of just the last week," an Obama campaign memo said.

According to the Times, Clinton loyalist James Carville now believes Obama will likely be the Democratic nominee.

In a speech at a South Carolina university, Carville said, "I think it's likely Obama is the nominee, but not certain. ... I would have preferred another result, but I'm going to be for him."

The newspaper quoted the outspoken strategist as saying, "Everybody is going to be with Obama," referring to Clinton's staff and backers. "I have an undated check written out for Obama. I'll send it when this is over."

Five more contests remain in the Democratic nominating battle, with a combined 189 delegates at stake. Oregon and Kentucky vote on May 20, Puerto Rico votes on June 1 and Montana and South Dakota vote on June 3.

Clinton is favoured again next week in Kentucky and Obama is favoured in Oregon.