Obama asks voters to 'believe' in new ad

Barack Obama is up with a new TV ad in Iowa today, "Believe," a stripped-down 60-second spot that has Obama speaking directly to voters -- no music, no frills, no raucous crowds, no nothing. Obama makes a personal appeal to viewers, asking them to believe that "we can actually change politics and bring an end to decades of division and deadlock."

"In twenty years of public service, I've brought Democrats and Republicans together to solve problems that touch the lives of everyday people," Obama says. "I've taken on the drug and insurance companies and won. I defied the politics of the moment, and opposed the war in Iraq before it began."

The theme is a familiar one, and it further underscores the Obama campaign's belief that next year's presidential election will be won by the candidate promising change, not, as rival Hillary Clinton contends, by the candidate with the most years in Washington. Clinton still leads in most state polls, but if Obama could eke out a win in the Iowa caucus, that might change everything.