Mann also says Obama balances his edgier ideas with words his audiences can embrace: In Detroit, an offer to help automakers with retiree health costs. In Philadelphia, a promise on merit pay that "I'm not going to do it to you, I'm going to do it with you." In Spartanburg, acknowledgment that the government needs to do more to help black men get education and jobs.
Some candidates this year have records and positions unpopular with the audiences they often face. Republican debates have featured Rudy Giuliani defending his support for legal abortion and John McCain explaining why he'd let millions of illegal immigrants earn citizenship.
Sen. Joseph Biden, D-Del., split with anti-war activists to support funding the Iraq war. New Mexico Gov. Bill Richardson, talking about universal health care at a union forum in February, said: "Our solution is always to increase taxes, and we shouldn't."
Obama has a history of taking messages directly to the source. Raised by a single mother from the age of 2, when his father went home to Africa, Obama addressed the problem of absentee fathers at his own Chicago church in 2005. After a skewering later that year by online activists, he asked them directly to be more civil and less judgmental.
Obama's "small lapses" from the party line this year "prevent him from being a generic Democrat," says Will Marshall, president of the centrist Progressive Policy Institute. "That makes him very interesting to a lot of people who might otherwise tune him out: independents, moderates, swing voters and would-be Republican defectors."