Senator Hillary Clinton kept her presidential hopes alive Tuesday with a convincing victory over rival Barack Obama in Pennsylvania's Democratic primary. The Democratic presidential race now moves on to primaries in North Carolina and Indiana on May Sixth. VOA National Correspondent Jim Malone reports from Washington.

Clinton needed a victory to remain in the Democratic nomination race. And, she got it -- with strong support from women, senior citizens and white working-class voters in Pennsylvania.

Clinton scored a substantial victory over Obama, who drew support from African-Americans, college-educated and more affluent voters.

An Obama victory in Pennsylvania could have ended Clinton's White House hopes. The former First Lady expressed appreciation to her supporters at a rally in Philadelphia.

"I might stumble and I might get knocked down, but as long as you will stand with me, I will always get right back up! Because, for me, in the end, the question is not whether we can keep America's promise, it is whether we will keep America's promise," she said.

Obama lost despite outspending Clinton in Pennsylvania by a margin of more than two to one. Obama remains ahead in the overall Democratic delegate count and in total popular vote won in the caucuses and primaries, so far. But Clinton has won most of the large states including Pennsylvania, Ohio, Texas, California and New York.

Obama addressed his supporters at a rally in Indiana and focused on his differences with the presumptive Republican nominee, Senator John McCain.

"We already know what we are getting out of the other party's nominee. John McCain has offered this country a lifetime of service and we respect that. But what he is not offering is any meaningful change from the polices of George W. Bush," he said.

Nine Democratic contests remain before the end of the caucus and primary season on June Third. It now appears that neither candidate will have amassed the number of delegates needed to win the nomination outright at the end of the primary season. That means uncommitted so-called "super delegates" could play a decisive role in the nomination battle sometime before the Democrats hold their national convention in Denver in late August.

Super delegates are party office holders and activists who can choose to support either candidate.

But many Democrats worry that the lengthy and bitter nomination fight between Obama and Clinton could the split the party and make it vulnerable in the general election in November against the presumed Republican nominee, Senator John McCain.

Political analysts like Stuart Rothenberg expect the Democrats to try and coalesce around a nominee, shortly after the primary season ends in early June.

"I think Democratic Party leaders believe it should end with the end of the primary calendar. They do not want this to drag on well into June or to July or, God forbid from their point of view, into August. They would like it to end pretty quickly," he said.

Both the Obama and Clinton campaigns are now focused on the May 6 primaries in North Carolina and Indiana. Obama is favored in North Carolina, but Indiana is rated as a toss-up and will likely receive the bulk of the campaign attention over the next two weeks.