By Jeff Mason
SAN FRANCISCO (Reuters) - U.S. President Barack Obama encouraged supporters on Monday to be "obsessive" about working for his re-election in the final weeks of the campaign, declaring himself confident that he would win on November 6.
Polls have narrowed in the race between the Democratic incumbent and Republican rival Mitt Romney since their debate last week, which most observers said the former Massachusetts governor won handily.
During a fundraising trip in California, the president sought to reassure his supporters about his chances, despite his debate performance.
"I am pretty competitive, and I very much intend to win this election," he said at a fundraising dinner that roughly 100 people paid $20,000 a ticket to attend.
"We're only going to do it if everybody is almost obsessive for the next 29 days," Obama said, noting that even though those in the room had donated money, there was more they could do to help the campaign.
At another fundraiser later in the evening with roughly 6,000 people, Obama ripped Romney for his promise during the debate to cut funding for public television and the popular children's program character Big Bird.
In an apparent reference to disgraced former sports start O.J. Simpson, who infamously fled police in a white Bronco after his ex-wife and a friend were found murdered, Obama said another popular children's character was making an escape as well.
"Elmo ... has been seen in a white ... suburban. He's driving for the border," Obama said to some laughter from the crowd.
Simpson was acquitted in the double murder trial in a case that was a flashpoint for race relations in the United States. A civil jury in 1997 found him liable for the deaths and ordered him to pay $33.5 million in damages to the murder victims' families.
Obama, the first black U.S. president, rarely discusses race or makes reference to racially-sensitive topics.
During the fundraiser, for which ticket prices started at $200, Obama also took aim at Romney's tax proposals and mocked the Republican for suggesting his proposals would not increase the U.S. deficit or hurt the middle class.
After finishing his western fundraising swing, Obama heads to Ohio on Tuesday to shore up support in a political battleground state that could be crucial for a second White House win.