(dpa) - Hillary Clinton scored a strong victory over rival Barack Obama in Pennsylvania's Democratic presidential primary Tuesday, giving the former first lady much needed momentum to keep her White House bid alive.
"It's a long road to 1600 Pennsylvania Avenue, (the famed White House address), and it runs right through the heart of Pennsylvania," Clinton told cheering supporters at a victory rally in Philadelphia.
"You made your voices heard, and because of you the tide is turning."
With 90 per cent of precincts reporting, Clinton had 55 per cent of the vote to 45 per cent for Obama, who had already left Pennsylvania Tuesday night to campaign in Indiana, which votes May 6.
"Now it's up to you, Indiana," Obama said at a rally in Evansville.
He congratulated Clinton on her Pennsylvania win but insisted that his campaign had "closed the gap" during the last six weeks of electioneering in the state. Clinton held an edge of as much as 20 points in polling several weeks ago.
Even with the Pennsylvania win, the former first lady is unlikely to make significant inroads into Obama's slim lead in delegates to the party's August nominating convention, which has prompted some Democrats to call for her to exit the race.
With the complex formula for assigning Democratic delegates from Pennsylvania, analysts said that Obama could end up with an equal number of the 158 convention delegates up for grabs Tuesday, despite Clinton's 10-point win.
But Clinton said that Pennsylvania had given her a significant shot of momentum for the nine intra-party contests remaining and vowed to continue the campaign.
"Some people counted me out and said to drop out," Clinton said, provoking loud boos from supporters. "But the American people don't quit, and they deserve a president who doesn't quit, either."
Obama, 46, admitted Monday that he expected a Clinton victory in the state. Clinton, 60, had said that any win would be significant after six weeks of tireless and increasingly negative campaigning.
Obama had also outspent Clinton by more than two-to-one in advertising across Pennsylvania. The Illinois senator had raised more than 40 million dollars nationally in March, compared to Clinton's 20 million dollars for the month.
Clinton's campaign on Monday admitted the New York senator is nearly 10 million dollars in debt. With nine contests left to go, Clinton used her Tuesday victory speech to make an impassioned plea for campaign donations.
"We can only keep winning if we can keep competing with an opponent who outspends us so massively," Clinton said, telling supporters to give money through her website.
Voters turned out in droves Tuesday across Pennsylvania, with the economy and health care on their minds and the fate of Clinton's presidential ambitions in their hands.
Obama started the day with a lead of 150 delegates in the national race to the Democratic presidential convention in August, where a majority of at least 2,024 delegates are needed to win the nomination.
Only about 500 delegates are left to be decided in the remaining nine contests. The states of Indiana in the Midwest and North Carolina in the south-east are next to vote, on May 6.
About one-fifth of the 4,047 total are so-called super-delegates - party leaders and activists who will likely be the deciding factor given the closeness of the race.
Pennsylvania was the largest remaining state, and the victory will bolster Clinton's argument to undecided super-delegates that she can take the big states needed to win the November 4 general election against presumptive Republican nominee John McCain.
Even before Tuesday's vote, Clinton had vowed to stay in the race regardless of the victory margin, and the New York senator's pugnacity was welcomed by her supporters outside a polling station in Hershey, Pennsylvania.
"Sometimes we've got to go through pain to gain, and if it's for the right person to be the nominee, it's absolutely necessary," said Suzanne Brinser, 40, after voting for Clinton.