New York Senator Hillary Clinton won the crucial Democratic presidential primary in Pennsylvania Tuesday, keeping her campaign alive.

US Democratic presidential candidate Senator Hillary Clinton (D-NY) addresses the crowd at a rally in Philadelphia, Pennsylvania, April 21, 2008.

With 72 percent of precincts reporting results, Clinton led rival Sen. Barrack Obama of Illinois by 54 percent to 46 percent, reported CNN.

"Some counted me out and said to drop out," the former first lady told supporters in a rally, calling the victory a "tide-turning" event.

"But the American people don't quit. And they deserve a president who doesn't quit either," she said.

Latest pre-election polls in Pennsylvania had shown Clinton maintaining a lead, but the margin had shrunk to single digit since April.

Clinton may be helped by the fact that Pennsylvania conducts "closed" primaries, meaning that only registered Democrats are allowed to vote.

She may have also benefited from the fact that Pennsylvania has a higher percentage of older, white and female population than that of the U.S. as a whole.

Past primaries saw Clinton wining heavily among these groups.

Exit polls showed her winning among Pennsylvania voters aged 65and over by a 23-point margin -- 61 to 38 percent.

She also received more support than Obama from white males, with 55 percent voting for her.

Clinton had acknowledged her White House bid was on the line in Pennsylvania.

"Well, I have to win," Clinton told ABC on Tuesday. "I believe that's my task. And I'm going to do everything I can to win."

Meanwhile, calling Pennsylvania an "uphill climb," Obama had said he did not predict a victory but "we feel good about where we are."

Pennsylvania will also hold a Republican primary, but Sen. John McCain of Arizona already has the 1,191 delegates needed to win the GOP presidential nomination, making the this primary a mere "beauty contest."

(Xinhua News Agency April 23, 2008)