"I worked on tons of tough bills. I was a leader on very controversial stuff," Obama said.
And he said he's glad to take the incoming fire, since it means he's a factor in the race.
"It actually beats the alternative," Obama said. "We wouldn't be doing well if people weren't confident that I could lead this country. . . . This election could be a defining moment for our politics."
Clinton, D-N.Y., would probably agree with that assessment. And she looks like she's going into the final pre-Christmas campaign days with some of her old swagger back.
"It's really picking up steam, and that's what I feel," she tells ABC's Cynthia McFadden in a "Nightline" piece that aired Wednesday night.
Clinton believes voters will ultimately look at her record: "We've gone through trying to decide, who would you rather have a beer with, and look at the results. I think we want to say, well, who would be the best president?"
And Clinton concedes that the troop surge in Iraq is having military benefits, but says it's irrelevant because Iraqi leaders aren't making political progress.
"So I don't think it matters at all. I think we need to begin to bring our troops home. In fact, I would argue that we not only need to bring them home because they should come home, but we need to bring them home because it's the only way to get the Iraqi government to focus on what it must do."
Among the Republicans, as we bid adieu to Tancredo, R-Colo., fresh evidence emerges of just how crazily tight the contest is. Romney's attacks notwithstanding, Huckabee, R-Ark., is the clear Iowa leader in the new ABC News/Washington Post poll: It's 35-27, and none of the other candidates are looking like they'll be factors on Jan. 3.
"Religion is driving the Republican presidential race in Iowa, with Mike Huckabee taking the lead on the strength of overwhelming support from evangelical voters -- and Mitt Romney falling behind over concerns about his Mormon faith," ABC Polling Director Gary Langer writes.
"Romney, for his part, holds a slight lead among the nearly eight in 10 Iowa Republicans who say his religion doesn't matter in their vote. But the remaining two in 10 say his Mormon religion makes them less likely to support him, and they overwhelmingly favor Huckabee by a large enough margin to put him in front overall."
"Republican women, particularly those who describe themselves as evangelicals and those who attend church regularly, are the primary force behind Huckabee's recent increases," Jon Cohen and Chris Cillizza write in The Washington Post.
"Women now support him over Romney by an 18-point margin; men divide their votes about evenly between the two."
And in a new national poll, "Rudy Giuliani has lost his national lead in the Republican field after a flurry of negative publicity about his personal and business activities, setting the stage for what could be the party's most competitive nomination fight in decades," John Harwood reports in writing up the new Wall Street Journal/NBC numbers.
"The results signal a dramatic shift in the nature of the Republican race: In a party with a history of rewarding established front-runners, there's no longer a front-runner of any kind."