SNEAK PEEK: Obama Zings Clinton in Final Debate

December 13, 2007— -- 21 Days Until the Iowa Caucuses

Barack Obama was quick on his feet at Thursday's Des Moines Register debate.

Asked by the moderator how he can deliver the kind of change he's promising when he is relying on a slew of former Bill Clinton advisers, Hillary Clinton tried to up the pressure, saying, "I want to hear that."

Without missing a beat, Obama shot back, saying, "Well, Hillary, I'm looking forward to you advising me, as well."

Watch it:

The snappy rejoinder, coming at the end of an otherwise listless debate, is sure to see some air time.

But the debate itself -- the final Democratic encounter before the Iowa caucuses -- will pass without much significance.

Right now, the question on everyone's mind is what will be the fallout from Bill Shaheen, co-chairman of Clinton's New Hampshire campaign, bringing up Obama's past cocaine use in a Washington Post interview. LINK

Shaheen stepped down from Clinton's campaign on Thursday.

"I would like to reiterate that I deeply regret my comments yesterday and say again that they were in no way authorized by Senator Clinton or the Clinton campaign," Shaheen said in a post-debate statement. "I made a mistake and in light of what happened, I have made the personal decision that I will step down ..."

Shaheen, who is married to New Hampshire's former governor raised questions about electability by telling the Washington Post earlier this week that Obama's admission of past drug use is something that Republicans are "certainly going to jump on."

"Shaheen said Obama's candor on the subject would 'open the door' to further questions. 'It'll be, 'When was the last time? Did you ever give drugs to anyone? Did you sell them to anyone?'" Shaheen said. 'There are so many openings for Republican dirty tricks. It's hard to overcome.'"

Despite his resignation, the Shaheen episode will likely rebound negatively for Clinton.

Although she has personally apologized to Obama, it was Clinton herself who recently raised the character question. LINK and LINK