Barack Obama raised $150 million (£87 million) last month, shattering his previous monthly record of $67 million and allowing him to swamp the airwaves in the final stretch of his presidential race against John McCain.

The huge haul — by far the biggest in presidential history — came as Mr McCain gave a robust performance in a television interview, where he predicted a close finish but also said that he had pondered the thought of defeat to Mr Obama, an outcome he said that he could live with.

Mr McCain, speaking moments after his old friend Colin Powell, the former Republican Secretary of State, had endorsed Mr Obama, said that a loss would not devastate him. He said that he had thought about it, “but I don't dwell on it”.

The Republican nominee continued: “I've had a wonderful life. I have to go back to Arizona and live ... with a wonderful family, and daughters and sons that I'm so proud of. I'm the luckiest guy you have ever interviewed and will ever interview. I'm the most fortunate man on Earth, and I thank God for it every single day.”

If he lost, he told Fox News Sunday, “don't feel sorry for John McCain and John McCain will be concentrating on not feeling sorry for himself”.

Mr McCain conceded that he was trailing, but pointed to several recent national polls showing the race tightening.

“Sure, I'm the underdog,” he said. Yet he added, in a reference to the near collapse of his campaign last summer: “Every time I've been ahead, I've messed up.” Mr McCain said that he had “started turning it around the other night” in the final presidential debate, adding: “I've been in enough campaigns to sense enthusiasm and momentum, and we've got it.”

Asked to repeat an assertion he made on Saturday that Mr Obama's economic proposals were socialist, Mr McCain said that his rival's plan to raise taxes on people earning more than $250,000 a year was a “redistribution of the wealth,” which “is one of the tenets of socialism”.

The Republican defended his use of automated robocalls to voters in swing states telling them that Mr Obama “has worked closely with domestic terrorist Bill Ayers”, the Vietnam-era radical who bombed government buildings. Mr McCain decried the use of such calls against him when he ran against George Bush in 2000.

He said that the content of the calls was “absolutely true”, unlike the smears directed against him during the 2000 South Carolina primary. “We need to know the full extent of that relationship [with Mr Ayers].”

Mr McCain said “you could make the argument” that Mr Obama was seeking to buy the election with his massive fundraising and spending. He decried his rival's decision to reverse a previous pledge to take public financing for his general election campaign.

“He broke his word to me and the American people,” Mr McCain said.

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