WASHINGTON/NEW YORK, Oct 17: Most opinion surveys released on Wednesday judged US President Barack Obama a clear winner of the second presidential debate, although supporters of his Republican rival Mitt Romney insisted he still had en edge.

According to a CBS survey, released an hour after the Tuesday night debate, said 37 per cent uncommitted voters saw Mr Obama as the winner while 30pc awarded the victory to Mr Romney. Thirty-three per cent called it a tie.

But the most surprising result came from the right-wing Fox News, which backs Mr Romney, but gave Mr Obama a 71pc to 29pc win over the Republican.

A CNN.com poll of 15,000 readers gave Mr Obama a decisive victory, 68pc to 32pc.

Public Policy Polling survey of a swing state, Colorado, gave President Obama a 48pc to 44pc win. Undecided voters sided more sharply with Mr Obama, 58 per cent to 36 per cent.

The CNBC also gave a huge victory to the president, 68pc to 28pc. But political analysts warned that most of its 62,000 respondents could be Democrats.

Monday’s polls differed sharply with those taken after the first presidential debate on Oct 3, when most opinion surveys declared Mr Romney the winner.

Respondents in the first debate praised Mr Romney’s aggressive style and said Mr Obama’s lukewarm approach disappointed them. For days after the first debate, polls continued to favour Mr Romney and a national aggregate of opinion surveys showed Mr Obama reached his lowest popularity rating – 45 per cent – after the first debate.

This brought tremendous pressure on the president to win the second debate. And minutes after the debate at New York’s Hofstra University began, it became obvious that this was going to be a different Mr Obama. He was full of energy, aggression and wit and responded appropriately whenever attacked.

Fifty-five per cent respondents to a survey noted that unlike the first debate, Mr Obama gave direct answers and confronted his rival whenever he tried to stare him down. Mr Obama also succeeded in improving his image as a handler of the domestic economy. Before Tuesday night’s debate, 71pc said they believed Mr Romney was more suitable for reviving an ailing economy.

Only 27pc favoured Mr Obama. After the debate, 34pc said Mr Obama could handle the economy better, although 65pc still backed Mr Romney.

But Mr Obama gained an edge in an area which is likely to play a crucial role in deciding the election: who is better for America’s large middle class? After the second debate, 56pc voters chose Mr Obama while  43pc backed Mr Romney.

Luckily for Mr Obama, the most sensitive issue of the current election campaign – a terrorist attack in Libya last month -- came up near the end of the debate. Republicans accuse him of mishandling the attack which killed the US ambassador and two other Americans.

Instead of defending how he handled the crisis, Mr Obama came out swinging at Mr Romney, accusing him of exploiting a security issue for scoring political points. “I stood in the Rose Garden and I told the American people and the world that we are going to find out exactly what happened, that this was an act of terror,” Mr Obama said. This baffled Mr Romney and he challenged Mr Obama’s claim.  “Get the transcript,” Mr Obama retorted.

But before Mr Romney could reply, Mr Obama received help from the moderator, CNN’s Candy Crowley. “He did, in fact, sir. He did call it an act of terror,” she said.  This stunned Mr Romney.  But this was not the only time during the 90-minute debate that the two candidates argued directly with each other.

Throughout the debate, Mr Obama insisted that he was for the middle class and was trying to bring better opportunities to them.

Mr Romney tried to counter this by asking the president three times if he’d looked at his pension.  “I don’t look at my pension.

It’s not as big as yours, it doesn’t take as long,” Mr Obama responded. He also reminded Mr Romney that at one of his campaign meetings, he had said that 47 per cent Americans were freeloaders.