PHILADELPHIA — Hillary Rodham Clinton ground out a gritty victory in the Pennsylvania primary Tuesday night, defeating Barack Obama and staving off elimination in their historic race for the Democratic presidential nomination.

"Some counted me out and said to drop out," the former first lady told supporters cheering her triumph in a state where she was outspent by more than two-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."

Her victory, while comfortable, set up another critical test in two weeks' time in Indiana. North Carolina votes the same day, and Obama already is the clear favorite in a Southern state with a large black population.

"Now it's up to you, Indiana," Obama said at a rally of his own in Evansville after Pennsylvania denied him a victory that might have made the nomination his.

He criticized John McCain, the Republican presidential nominee-in-waiting, by name as offering more of the same policies advocated by President Bush. And he took aim at Clinton without mentioning her by name. "We can calculate and poll-test our positions and tell everyone exactly what they want to hear," he said. "Or we can be the party that doesn't just focus on how to win, but why we should."

In a campaign marked by increasingly personal attacks, Clinton won the popular vote in Pennsylvania about 55 percent to Obama's 45 percent.

Democratic party rules require Pennsylvania to award its 158 pledged delegates proportionately by congressional district, with greater representation for districts that vote heavily Democratic. That gives more delegates to African-American districts, which Obama won overwhelmingly.

As a result, Clinton will not win significantly more Pennsylvania delegates than Obama.

A preliminary tabulation showed her gaining at least 66national convention delegates to 57 for Obama, with 35 still to be awarded.

That left Obama with 1,705.5 delegates, and Clinton with 1,575.5, according to the AP tally.

Clinton scored her victory by winning the votes of blue-collar workers, women and white men in an election where the economy was the dominant concern. Obama was favored by blacks, the affluent and voters who recently switched to the Democratic Party, a group that comprised about one in 10 Pennsylvania voters, according to the surveys conducted by The Associated Press and the TV networks.

More than 80 percent of voters surveyed as they left their polling places said the nation was already in a recession.

A six-week campaign allowed time for intense courtship of the voters.