"How many of you have college debt you're paying right now?" New York Sen. Hillary Rodham Clinton last night asked the crowd of thousands in Soldiers & Sailors Military Museum and Memorial.

Scores of hands went up in the audience in front of her, and one particularly prominent one sparked laughter as it rose amid the VIPs flanking her on the grand Oakland stage.

With a broad smile, Mrs. Clinton noticed Pittsburgh Mayor Luke Ravenstahl, who had just endorsed her Democratic presidential candidacy.

"If you're the youngest mayor in America, you probably do have college debt," she observed. "Well, here's an offer that the mayor might be able to take advantage of. If you're willing to do public service, mayor, like teaching or nursing or law enforcement -- or mayoring -- we will forgive your debt over a period of years."

Like a lot of campaign promises, it's probably not one that Mr. Ravenstahl can count on. But he enthusiastically joined Gov. Ed Rendell and Allegheny County Chief Executive Dan Onorato in welcoming Mrs. Clinton to the Pittsburgh kickoff of her Pennsylvania primary campaign.

The crowd that had found refuge from the cold rain outside heard a generally upbeat speech, with the Bush administration as its chief target. But Mrs. Clinton again tried to put her Democratic rival, Illinois Sen. Barack Obama, on the defensive over his support for a 2005 energy measure backed by the Bush administration.

"There's a big difference between me and my opponent in this campaign," she said. "You know both Senator Obama and [Republican Arizona] Senator McCain talk a lot about taking on the special interests. But when it came time to vote on the 2005 energy bill written by [Vice President] Dick Cheney, Senator Obama voted yes for more giveaways to the oil companies," she said, stirring boos from her partisans. "I voted no."

Mrs. Clinton's criticism, a staple of recent speeches, drew a quick response form the Obama campaign, which shot back with a statement assailing her for taking campaign contributions from oil company lobbyists.

Mr. Obama on Monday will be in Pennsylvania for a rescheduled visit to Beaver County and a stop in Scranton. Mrs. Clinton had started her Pittsburgh foray with a stop at a family-owned gas station in Bloomfield, enlisting it as a backdrop for her criticisms of Mr. Obama and of the Bush administration over rising gas prices.

Pointing to estimates that average Pennsylvanians are paying $1,000 more for gas annually than they did before President Bush took office, Mrs. Clinton highlighted several of her proposals to promote energy independence, including the promotion of biofuels, a $50 billion program to prod oil companies to invest in clean energy production.

Bill Burton, press secretary for the Obama campaign, issued a statement denouncing the latest Clinton attack, a replay of an indictment of her rival that she had pressed Tuesday in Harrisburg. "Hillary Clinton should start telling the truth about Barack Obama's record and her own," he said. "The truth is that Barack Obama voted for a bill that actually raised taxes on oil companies and made the largest investment in renewable energy in our nation's history."

Mrs. Clinton made her Bloomfield stop at the beginning of a campaign swing that was to end today with an appearance at the St. Patrick's Day Parade. Between swipes at her opponents, she called for a federal probe of oil prices. "What's going on deserves further scrutiny," she said. "A lot of it doesn't make sense to me."

She criticized Mr. Cheney's visit to Mideast oil producers and said: " I will not be a president who holds hands with the Saudis; I will be a president who holds the Saudis accountable."

Mrs. Clinton said that if she were president, she would consider releasing oil from the government's strategic petroleum reserve to put downward pressure on prices, and that, at a minimum, the government should halt new purchases for the reserve while prices remain at historically high levels.

The Soldiers & Sailors crowd enthusiastically welcomed her familiar promises to reform the nation's health care system and end the war in Iraq.

"We need to rebuild the relationship between our president and our people," she said. "The best way for you to think about this is who would you hire for this job?"

That sparked chants of "Hill-a-ry, Hill-a-ry, Hill-a-ry," as she ticked off a list of priorities for her administration.

Mrs. Clinton lingered long after the rally's formal close, signing campaign signs and other memorabilia for a mixed but mostly female crowd that pressed toward the stage. Many came away laughing and yelling in triumph as they displayed the trophy of her signature.

For Mrs. Clinton, still behind in the delegate count, but buoyed by her recent popular-vote wins in Texas and Ohio, it was the fourth big crowd she has drawn as she points toward the Pennsylvania primary April 22. The addition of Mr. Ravenstahl and Mr. Onorato to her store of endorsements underscored the broad support she has collected from the state's senior officials, led by Mr. Rendell.

Recent polls have consistently shown her leading here. A SurveyUSA poll released this week by KDKA-TV showed that in addition to her overall Pennsylvania lead, the state's southwest and northeast corners -- where she will again campaign today -- were particular pockets of strength for her with six weeks of campaigning still to go.