Obama was questioned about controversial remarks by his former pastor, the Rev. Jeremiah Wright, that had forced Obama to deliver a major speech about race, and asked how he would respond when Wright's sermons were replayed on television in the fall campaign.
After noting that he had "disassociated" himself from Wright's remarks, Obama said he did not think voters would be "distracted once again by comments not made by me, but somebody who is associated with me that I have disowned."
"You've disowned him?" asked Stephanopoulos.
"The comments that I disowned," said Obama.
Clinton criticized Obama's association with Wright, saying the minister had put a message from the leader of Hamas in the church bulletin and had "relationships" with Nation of Islam leader Louis Farrakhan.
"These are problems, and they raise questions in people's minds," Clinton said.
Obama, who once said that wearing a flag pin was a substitute for "true patriotism," said he was "absolutely confident" that his reluctance to do so would not be an issue in the fall campaign.
In a faceoff with McCain, he said, voters "are not going to be question my patriotism," they will be asking, "How can you make people's lives a little bit better?"
Clinton was forced to apologize again for her erroneous claim that she landed in Bosnia under sniper fire in 1996, which she had repeatedly used as an example of foreign policy experience.
In a video clip, a voter from Pittsburgh, Tom Rooney, said Clinton had lost his vote over the incident.
Clinton said she had been "embarrassed by it," but she laughed derisively when Obama contended that his campaign had not exploited the issue.
"We both have said things that, you know, turned out not to be accurate," Clinton said. "That happens when you're talking as much as we have."
The debate brought pledges from both candidates that they would not raise taxes on those making less than $250,000 (Clinton) or $200,000 to $250,000 (Obama). But Obama was forced to acknowledge that he has proposed raising the Social Security payroll tax on those earning more than about $100,000.
Obama refused to say whether an Iranian attack on Israel would be treated as an attack on the United States, but did say that it would be "unacceptable" and that he "would take appropriate action" as president.
Clinton promised "massive retaliation."
Recent polls suggest that Clinton's intensive effort to exploit Obama's "bitter" comment has not made any significant impact in Pennsylvania. She appears to be ahead by margins of 5 to 14 percentage points, though Obama has not gained significantly since the gaffe.
The 21st Democratic debate was the fourth time that Obama and Clinton had met one-on-one. Clinton has agreed to an April 27 debate in North Carolina, one of the next two primary states, but Obama has not.
Last night's debate came just six days before Pennsylvania Democrats vote in the biggest contest left on the primary calendar.
paul.west@baltsun.com
