(Agencies)
Updated: 2008-02-27 09:19

CLEVELAND, Ohio -- Beset by slumping poll numbers, Hillary Clinton had a last chance in a one-on-one debate Tuesday to slow Barack Obama's roaring momentum before two White House nominating clashes next week.

US Democratic presidential candidate Hillary Clinton speaks during a campaign event in Washington, DC on February 25, 2008. Beset by slumping poll numbers, Clinton has a last chance in a one-on-one debate Tuesday to slow Barack Obama's roaring momentum before two pivotal nominating clashes next week. [Agencies]

The besieged former front-runner, her hopes on the edge ahead of must-win contests in Ohio and Texas on March 4, hopes to halt an Obama surge that has seen her Democratic rival snap up 11 straight electoral victories.

Obama, carving out wide leads in national Democratic polls, landed Tuesday's first morale-sapping blow, capturing the endorsement of former party White House hopeful and liberal champion Senator Chris Dodd.

"I am sure we will have a vigorous debate," Obama said as he accepted the Connecticut senator's backing here Tuesday.

"I would expect her to argue vigorously her case for why she should be president and I am sure she will point out differences that she has with me."

Obama, 46, said he expected the clash to be conducted in a "civil fashion" but knows Clinton may try to snare him with the same searing tone seen in her recent barrage of attacks on his presidential credentials.

His campaign manager David Plouffe previewed a possible Obama line of defense in a fundraising email to supporters, after the New York Times reported she was preparing a "kitchen sink" negative barrage.

"This is the same stale, Washington playbook that has driven so many Americans away from the political process," Plouffe wrote.

Obama rode a head of steam into the Cleveland debate as new polls suggested Clinton's support was collapsing and as newspapers reported internal conflict was battering her campaign.

A CBS News/New York Times survey gave Obama a 54 percent to 38 percent lead among Democrats nationwide. A USA Today poll had him up 51 percent to 39 percent nationally among Democratic voters.

There was more alarming news for Clinton, a day after a poll showed Obama leading in Texas for the first time. A Rasmussen Reports survey Tuesday showed Obama had cut her lead among Ohio Democrats to just five points, as she led 48 percent to 43 percent. Last week, Obama had 40 percent, and the week before 38 percent.

Ohio Governor Ted Strickland, trying to deliver his state for Clinton, said her campaign's blanket get-out-the-vote bid would go on full tilt until Tuesday.

Clinton's tone in the debate will be closely watched. In a debate last week in Texas, she had been expected to go on the offensive, but only unleashed a few poorly received attacks before ending on a valedictory note.

Another of the New York senator's supporters, Massachusetts congressman Jim McGovern, said Clinton would zero in on issues, and not be distracted by polls of the Democratic "horse race."

"She needs to talk to the American people and forget about all this other stuff that the media and the chattering class seem to be obsessed with," he told MSNBC.

The debate takes place a day after a photograph emerged of Obama dressed in a Somali robe and turban, a reminder of his African heritage in a campaign where the issues of race and religion have always lurked in the background.

Plouffe accused the Clinton team of "shameful, offensive fear-mongering," but Clinton's camp denied it had passed the photo to the Drudge Report website.

Aides to presumptive Republican nominee John McCain meanwhile accused the Democrats of playing election games in a legal row over his attempts to back out of receiving public money for his White House campaign.

"Everything we did here was legal, ethical and proper," McCain spokeswoman Jill Hazelbaker said, accusing Obama of "backpedalling" on whether he too would take public funds.

Senator McCain is trying to withdraw from an agreement with the Federal Election Commission to take FEC funds, which carry a strict limit on how much a candidate can spend in primary and general election campaigns.

Obama, buoyed by record-breaking fundraising, is accused by McCain of reversing a pledge to accept public spending limits. But the Illinois senator says he never made the kind of outright promise claimed by McCain.