Sarah Palin unleashed by John McCain for attacks on Barack Obama

Sarah Palin's comments marked the first time the McCain campaign itself, rather than his allies, have questioned Mr Obama's patriotism Photo: AP Mr McCain's aides had kept Mrs Palin, 44, under wraps as much as possible, beginning to fear she might become a liability. But fresh from an assured performance in the vice-presidential debate, and with Barack Obama, the Democratic nominee, surging ahead in the opinion polls, Mr McCain threw caution to the wind and ordered that Mrs Palin, 44, attack his White House rival repeatedly and ferociously.

Let off the leash on Saturday, Mrs Palin accused Mr Obama of "palling around with terrorists who would target their own country" in a reference to him once being a member of a Chicago community group with William Ayers. The former member of the Weather Underground was last active in the domestic terrorist group during the presidential candidate's childhood.

She added: "This is not a man who sees America as you see America and as I see America."

The Obama campaign responded that Mrs Palin's attack was "gutter politics" and other supporters suggested that the McCain campaign was merely trying to distract voters from the economy, on which Mr Obama is deemed to be more competent.

However, more worrying for Mr McCain is that her first pitbull-like assault on Mr Obama appeared yesterday to have backfired spectacularly as Democrats queued up to dish electoral dirt on Mr McCain.

They believe that John Kerry lost to George W. Bush in 2004 because he did not respond strongly enough to Republican attacks. But they do not intend to stand idly by this time.