US President George W. Bush and his campaign officials on Thursday dismissed polls showing Senator John Kerry had won the three presidential debates, saying any gain Kerry had from them would prove fleeting.

"The pundits and the spinners, they all have their opinions but there's only one opinion that matters and that's the opinion of the American people on Nov. 2," local media reports quoted Bush as telling reporters on Air Force One on the flight to Las Vegas from Arizona.

Several snap polls after the 90-minute debate in Tempe, Arizona Wednesday night showed Kerry outperformed Bush, one of them with an edge of 13 percentage points. Kerry was the clear winner in their first debate and the second debate was widely regarded as a tie.

Marc Racicot, Bush's campaign chairman, questioned the credibility of the snap polls, saying Bush gave his best performance on the last debate. “He was in command of the facts. He was in command of the issues. He was relaxed. He was confident," he told reporters in Tempe.

Racicot said Kerry "did provide himself some temporary assistance" with the first debate, but that assistance "got more leavened" in the second debate and "then began to dissipate" with the last performance.

He said any boost Kerry got from the debates would be fleeting."I think it was temporary."

Bush and Kerry launched their final sprint Thursday to the Nov.2 election. Both men went to Nevada, with Bush attending a rally with Republican governors in Las Vegas and another rally in Reno while Kerry was scheduled to speak in Las Vegas at an American Association of Retired Persons event.