Needing big wins in Ohio and Texas to revive her hopes of getting her party's nomination for president, the former first lady tried but, observers believed, failed to deliver a damaging blow.

'She wanted to achieve more. She wanted Senator Obama to stumble,' one of the debate's two moderators, Mr Tim Russert, told NBC's Today show yesterday morning. 'But both candidates articulated their positions on the issue and there were no major mistakes.'

Mr Russert was echoing most analysts who believed that Mrs Clinton's performance did not jolt her flailing campaign.

She accused the Illinois senator of copying the scare tactics of health insurers and Republicans in attacking her health-care plan.

Mr Obama, 46, countered by criticising Mrs Clinton's vote to approve the Iraq war and her support of the record of her husband - former president Bill Clinton - in forging foreign trade agreements.

That undoubtedly has touched a nerve with voters in Ohio, who have seen their state's economy devastated by the movement of factories - and jobs - overseas.

Just six months ago, the Hoover Company - maker of the premier vacuum cleaner which was the prime industry in North Canton, just south of Cleveland - closed its original factory which once employed up to 2,400 people.

Ironically, it moved to China, the country from which the city adopted its name.

Mrs Clinton claimed that she had always opposed the North American Free Trade Agreement (Nafta), the kind of trade agreement worked out by her husband with Mexico and Canada that set the pattern for similar agreements in Asia.

Mr Obama said this was news to him. He pointed out that she praised the deal as good for New York during her senatorial campaign.

The man who could become the first African-American president also took aim at Mrs Clinton's campaign theme that, due to her long experience in Washington, she is the only one ready to be president from 'day one'.

Mrs Clinton, 60, was part of the old Washington crowd and 'had driven the bus into the ditch' by voting for the war in Iraq, said Mr Obama, who spoke out and voted against the invasion.

Acknowledging that he had later voted in favour of a motion on Iraq, he countered that 'once we had driven the bus into the ditch, there were only so many ways we could get out'.

Ohio has 141 delegates up for grabs while Texas has 193, and even a narrow win or loss for Mr Obama in one of those states could end Mrs Clinton's bid, as delegates are apportioned according to the percentage of votes they win.

An MSNBC online poll showed Mr Obama winning the debate 82 per cent to 17 per cent.

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

zach@sph.com.sg