NEW YORK, April 23: Senator Hillary Clinton kept her presidential hopes alive on Tuesday night, winning a crucial victory in the Pennsylvania primary over her rival Senator Barack Obama by 10 points.

“Some counted me out and said to drop out,” Mrs Clinton told supporters cheering her triumph in a state where she was outspent by almost three-to-one. “But the American people don’t quit. And they deserve a president who doesn’t quit either.

“Because of you, the tide is turning,” she told her voters.

With 99 per cent of the vote counted by Wednesday morning, Mrs Clinton had 55 per cent of the vote to 45 per cent for Senator Obama.

However, the political pundits here observed that it was unclear whether Mrs Clinton’s margin of victory in Pennsylvania would be enough to stop calls that she should cede the field to Obama.

Mrs Clinton’s victory set up her next critical test in two weeks in Indiana. North Carolina votes the same day, and Senator Obama already is the clear favourite there, thanks to the state’s large black population.

“Now it’s up to you, Indiana,” Senator Obama said at a rally after Pennsylvania denied him a victory that likely would have clinched the nomination for him. But the going is still tough for the New York senator, who has been trailing her rival in the delegate count and has been crushed in the money race.

Experts here say that Mrs Clinton’s best hope for winning the Democratic nomination is to crank up her fundraising machine and capitalise on Tuesday night’s victory, which helped close the gap on the popular vote and could sway superdelegates, who could vote for either candidate at the Democratic National Convention.

With her Pennsylvania win, Mrs Clinton can also boast a strong record in the big states as she attempts to persuade the superdelegates to look past Senator Obama’s delegate advantage and his lead in the popular vote. In addition to Ohio, she has won primaries in Texas, California and her home state of New York, while Senator Obama won his home state of Illinois.

Money has become a major obstacle for Mrs Clinton, whose latest filings show that she has $10.3 million in outstanding debt and just $9.5 million in the bank. Senator Obama, meanwhile, has shown tremendous fundraising prowess, raising $42 million in March and showing $43 million in his war chest.

For Mrs Clinton to remain competitive, she would need a huge bounce out of her Pennsylvania win and for donors nationwide to open up their chequebooks, most experts here say.

One thing is sure; the battle for Democratic nomination will go on until August, the time of the national convention in Denver, Colorado.