Democrat Barack Obama has opened up a 6-point lead over Republican rival John McCain in the presidential race according to the latest poll.
The Reuters-C-Span-Zogby tracking poll has Mr Obama leading Mr McCain 49 to 43%.
The four-day tracking poll is Mr Obama's widest lead since the poll was started on Tuesday.
It was up from a 4-point lead on Saturday.
The poll has a margin of error of 2.9%.
Pollster John Zogby said Barack Obama's lead is now statistically significant.
With just over three weeks to go before the November 4 election, the poll showed Mr Obama gaining traction among independent voters who now back him by a 21-point margin.
Among women, another crucial group, the Illinois senator held a solid 12-point lead, while the two candidates were tied among male voters at 45% apiece.
The rolling tracking poll surveyed 1,206 likely voters in the presidential election. In a tracking poll, the most recent day's results are added while the oldest day's results are dropped in an effort to track changing momentum.
Obama praises McCain
Mr Obama has praised Mr McCain for trying to tone down the vitriol of the US presidential race.
At his own rally on Saturday, Mr Obama said he appreciated Mr McCain's attempts to restore an atmosphere of respect to the campaign.
"I want to acknowledge that Senator McCain tried to tone down the rhetoric in his town hall meeting yesterday. I appreciated his reminder that we can disagree while still being respectful of each other."
The Republican senator has been forced to not only tone down criticism of Mr Obama, but to defend him, as supporters try to cast a slur on the Democratic candidate.
Speaking in Minneapolis, Mr McCain - who had escalated character attacks on Mr Obama in recent days - found himself in the unlikely role of defending his rival in the face of sometimes hostile questions from frustrated Republican loyalists, stunned by the Democratic senator's lead in the polls.
He drew boos from a crowd packed into a high school gymnasium when he insisted to a sceptical supporter that Obama was a "decent person and a person that you do not have to be scared (of) as president of the United States."
The woman had said: " "I don't trust Obama. I have read about him. He's an Arab."
Mr McCain's supportive comments were drowned out by a chorus of boos from the audience. He then added that he thought he would be a better president than Senator Obama.
A series of negative adverts aimed at casting doubt on Mr Obama has also backfired on the Republican camp.
In addition, a report on Mr McCain's running mate Sarah Palin, has found that she had abused her powers as Governor of Alaska.