(Agencies)
Updated: 2008-04-17 08:48

PHILADELPHIA, Pennsylvania - Hillary Clinton faced a high-stakes debate with Democratic foe Barack Obama Wednesday, as daunting poll numbers lengthened her odds on a comeback in the White House race.

Democratic presidential hopeful New York Senator Hillary Clinton (R) greets union supporters following her speech at the Building Trades National Legislative Conference at the Washington Hilton hotel in Washington, DC. Clinton Wednesday faced lengthening odds for her White House bid as polls showed her personal ratings diving and her prospects clouding over in several key primaries. [Agencies]

Clinton was under intense pressure to change the complexion of the contest in the one-one-one clash with Obama in Pennsylvania, which holds the next nominating contest in the roller-coaster Democratic race next Tuesday.

The New York senator has been attacking Obama for days over his comment that some small-town Americans were "bitter," but latest opinion surveys suggested her rival had escaped serious immediate damage.

Obama has also spent the last six weeks since the Ohio and Texas primaries battling the fallout from incendiary comments by his former pastor, Reverend Jeremiah Wright.

Polls show Clinton has stalled Obama's attempt to catch her in Pennsylvania, but her lead of around six points did not suggest the kind of blowout win she needs to sow doubts about Obama's viability in the minds of top party leaders.

Clinton has been written off before and pulled off surprising comebacks, but her White House hopes are on thin ice because she trails Obama in nominating contests won, elected delegates and the popular vote.

Her only chance now is to convince nearly 800 Democratic grandees called superdelegates that Obama cannot win November's general election against Republican John McCain.

There was more grim news for Clinton in a Washington Post/ABC News poll which gave Obama a 10-point lead when Democrats nationwide were asked who they would like to see go up against McCain.

Obama was up two-to-one among Democrats asked who was most electable in a general election, undermining Clinton's quest for the hearts of the superdelegates.

And more Americans had an unfavorable view of her than at any time since the Post and ABC started measuring the question in 1992.

Some 54 percent of those asked had an unfavorable impression of the former first lady -- up from 40 percent, after her famous comeback victory in the New Hampshire primary in early January.

A Los Angeles Times/Bloomberg poll meanwhile showed Obama up 40 percent to 35 percent in Indiana, another rust-belt primary on May 6, where she needs a win. An earlier Survey USA poll in the state, however, had Clinton up 16 points.

The LA Times poll also had Obama up 13 points in North Carolina, which also votes on May 6. Other surveys suggest the man bidding to be the first African-American president will benefit from the southern state's large number of black Democratic voters.

Clinton was likely to use Wednesday's debate to further challenge Obama over his remarks at a party fundraiser in San Francisco, which her aides believe could make it tough for him to win over blue-collar voters in crucial swing states in a general election.

Obama will get another chance to talk his way out of the spat, which has prompted Clinton and McCain to brand his comments as "elitist."

He played down the impact of the row on Wednesday, as he met Jewish community leaders in Philadelphia.

"I'm suggesting people are bitter about the state of their economic lives (and) the Washington beltway hall of mirrors has just gone nuts," Obama told reporters.

"Then they open the paper look at the polling yesterday it turns out most people it hasn't had an impact in terms of how they're thinking."

Obama got a vote of confidence on Wednesday from rock megastar Bruce Springsteen, who said the Illinois senator's comments on working-class voters had been ripped out of context.

"I've been following the campaign and I have now seen and heard enough to know where I stand. Senator Obama, in my view, is head and shoulders above the rest," Springsteen wrote on his website.

"He speaks to the America I've envisioned in my music for the past 35 years, a generous nation with a citizenry willing to tackle nuanced and complex problems."

Obama also won backing from the American Hunters and Shooters Association, a newly formed rival to the zealously pro-gun National Rifle Association.

The AHSA endorsed Obama for president, citing his vote in 2006 for a law that forbids authorities from confiscating legally owned firearms during a Hurricane Katrina-type disaster.