Hillary Clinton and Barack Obama entered the final phase of an increasingly negative US presidential fight today, and Clinton said her decisive Pennsylvania win proved she was the best candidate to lead the Democrats back to the White House.
Supporters of Democratic presidential hopeful Senator Hillary Clinton celebrate her victory at a campaign gathering on Pennsylvania primary night in Philadelphia
Mrs Clinton's 10-point win paid immediate dividends in fund-raising for the cash-strapped New York senator and shaved off some of Mr Obama's lead in popular votes and in delegates who select the Democratic nominee at the August convention.
The New York senator still faces a daunting task trying to overtake Obama's lead in pledged delegates who will help select the Democratic presidential nominee at the August convention.
She said Obama's failure to knock her out of the race, despite outspending her in Pennsylvania more than 2-to-1, cast doubt on his ability to capture the big states Democrats need in November's election race against Republican John McCain.
"I've won the states we have to win - Ohio, now Pennsylvania," Clinton said. "If you look at the broad base of support that I have accumulated it really is the foundation on which we build our victory come the fall."
Both candidates immediately looked to the next round of contests on May 6th in North Carolina, where Mr Obama is favoured to win, and Indiana, which is considered too close to call.
"Some people counted me out and said to drop out, but the American people don't quit and they deserve a president who doesn't quit either," Mrs Clinton told cheering and chanting supporters in Philadelphia, where she was joined on stage by her husband, former president Bill Clinton, and daughter Chelsea.
Mrs Clinton, whose campaign is in debt and running low on cash, urged backers to visit her website and donate. In television interviews today, she said she raised $3 million dollars in the hours after she he won Pennsylvania.
Mrs Clinton survived a heavy advertising onslaught in Pennsylvania by Obama, who outspent her by more than 2-to-1 in the first Democratic nominating contest in six weeks. She won with 55 per cent of the vote to Obama's 45 per cent.
The contest in Pennsylvania, where 158 delegates were at stake, opened the final phase of the Democratic duel for the right to face Republican John McCain in November's presidential election. Nine more contests are scheduled before the voting ends on June 3rd.
Mr Obama, who narrowed a 20-point Clinton lead in opinion polls before falling short, already was looking ahead. He left Pennsylvania before the polls closed for an evening rally in Indiana.
"There were a lot of folks who didn't think we could make this a close race when it started," Mr Obama said in Evansville. "Six weeks later, we closed the gap. We rallied people of every age and race and background to our cause."
Turnout was heavy and a record number of Pennsylvanians had registered to vote.
The result followed Mrs Clinton's popular vote victories in Ohio, California, New Jersey and Texas, fuelling her argument she is the Democrat who can capture the big and diverse states where the party will need to do well in November.
Mr Obama, an Illinois senator, won nine of every 10 black voters and led among young and male voters. Mrs Clinton won the support of blue-collar workers, elderly voters and more than half of women.
She also won 58 per cent of those who decided in the last week, when Mr Obama was on the defensive in a debate over a series of campaign controversies and Mrs Clinton questioned his toughness in an ad featuring images of al Qaeda leader Osama bin Laden.
Voters were not happy with the race's negative tone. About two-thirds of Pennsylvania voters thought Mrs Clinton unfairly attacked Mr Obama, while about half thought Mr Obama had unfairly attacked Mrs Clinton, the polls showed.
Mr Obama has a nearly insurmountable lead in popular votes won during the first three months of the primary battle and in delegates. But neither candidate can clinch the nomination without the help of superdelegates - nearly 800 party insiders who are free to support either candidate.
The victory in Pennsylvania cut Mr Obama's lead in votes won during the nomination battle to about 500,000. A partial delegate count in the state gave Mrs Clinton 75 delegates to Mr Obama's 65, according to MSNBC.
The MSNBC count gave Mr Obama 1,720 delegates overall to Mrs Clinton's 1,588, both well short of the 2,024 needed to clinch the nomination.