With just two days to go before the Indiana and North Carolina primaries, the Democratic presidential candidates appeared on rival morning talk shows yesterday to spar about gas tax holidays, Iran and superdelegates.

Sen. Barack Obama spent the first 18 minutes on NBC's "Meet the Press" with Tim Russert defending the timing of his decision to break from his former pastor, Rev. Jeremiah S. Wright, while on ABC's "This Week with George Stephanopoulos," Sen. Hillary Rodham Clinton pushed back at criticisms of her proposal to suspend the federal gasoline tax for summertime drivers.

Campaigning in Indiana, where he narrowly trails Mrs. Clinton, and faced with a dwindling lead in North Carolina, Mr. Obama has tried to redirect the focus away from Mr. Wright, who retired last year as longtime pastor at Trinity United Church of Christ in Chicago but whose incendiary sermons have circulated on the Internet, creating serious political problems for Mr. Obama.

In his appearance at the National Press Club last week, Mr. Wright repeated his claims that the U.S. government created the AIDS crisis and that the United States was responsible for the terrorist attacks on Sept. 11, 2001.

"Not only did he amplify some of those comments and defend them vigorously, but he added to it. He put gasoline on the fire," Mr. Obama told Mr. Russert during the hour-long interview. "What really changed was a sense that he was going to double down on the statements that he had made before.

Asked why it took so long to break with Mr. Wright -- whom Mr. Obama disinvited from giving the invocation when the Illinois senator announced his presidential candidacy last year -- Mr. Obama said he was worried about hurting his longtime pastor, even while telling Mr. Wright his sermons could be "kind of rough."

"I was sorry that he felt, that he felt hurt by that decision. And ... that may be a fault of mine that I own up to, which is that I'm concerned about how other people feel, particularly somebody who I've known for quite some time. But, but that doesn't detract from ... my belief that, ultimately ... what he has been saying about the United States over the last several months and over the last several years, particularly some of the statements that I had not heard before, are contrary to who I am and what I stand for."

"My commitment, as I said, Tim, is to the church, not to a pastor."

During her appearance on ABC, Mrs. Clinton declined to engage Mr. Obama on the issue, saying it was time to "definitely move on" from Mr. Wright, although she noted "there's no doubt [the Democratic party's superdelegates] talk about it.

"But what people I think are more interested in is what we would do and what kind of president we would be."

The two candidates, who taped their appearances a few blocks apart in Indianapolis, did clash over Mrs. Clinton's claim, first made last month, that the New York senator would "totally obliterate" Iran if it attacked Israel.

Mr. Obama suggested Mrs. Clinton was a political opportunist, comparing her to President Bush.

"It's not the language we need right now, and I think it's language reflective of George Bush," he said, noting that his opponent had "scolded me on a couple of occasions [for speculating about Iran], yet a few days before an election, she's willing to use that language."

Mrs. Clinton was unrepentant when asked about her statement by Mr. Stephanopoulos.

"Why would I have any regrets? I'm asked a question about what I would do if Iran attacked our ally ... and, yes, we would have massive retaliation against Iran," Mrs. Clinton said. "I don't think they will do that, but I sure want to make it abundantly clear to them that they would face a tremendous cost if they did such a thing."

Mrs. Clinton fielded queries by both Mr. Stephanopoulos -- who noted at the outset that he had worked for the Clinton administration between 1991 and 1996 -- and an audience comprising her supporters, Obama supporters and undecided voters.

She also defended her gas tax holiday proposal, calling it a short-term fix that would benefit long-distance commuters in North Carolina and Indiana -- those who "drive for a living, who commute long distances, who would save money if the oil companies paid this $8 billion this summer, instead of it coming out of the pockets of consumers."

Her federal gas tax moratorium would also be coupled with a long term plan to ease this country's dependence on foreign oil.

Asked to name a single economist who supported it, Mrs. Clinton instead got in a subtle dig at her opponent, who she has repeatedly tarred as an elitist after Mr. Obama made remarks describing small-town Pennsylvanians as clinging to guns and religion out of bitterness with government's failure to help them.

"I think we've been for the last seven years seeing a tremendous amount of government power and elite opinion basically behind policies that haven't worked well for the middle class and hard-working Americans," she said.

"You know, it's really odd to me," she added, "that arguing to give relief to the vast majority of Americans creates this incredible push-back. When the federal government, through the Fed and the Treasury, gave $30 billion in a bailout to Bear Stearns, I didn't hear anybody jump up and say, 'That's not going according to the market. That's rewarding irresponsible behavior.'

"We've got to get out of this mind-set where somehow elite opinion is always on the side of doing things that really disadvantage the vast majority of Americans," she said.

She also managed to zing Mr. Stepanopoulos after he repeatedly questioned her opposition to the North American Free Trade Agreement, which her husband, Bill Clinton, introduced during his presidency.

Bristling at the ABC host's suggestion that the Clinton administration didn't do enough "to address the downside of globalization and therefore failed the workers in Indiana and the workers of the West, "she cited the booming economy of the 1990s "that created 23 million new jobs. More people were lifted out of poverty in any time in our near history. It was an economy that worked for everyone -- not just the rich, the wealthy and the well connected -- but there were underlying issues that we didn't understand fully."

Then, turning to the audience, she added, "Now, you remember this, because George did work in that '92 campaign: George and I actually were against NAFTA. I'm talking about him in his previous life, before he was an objective journalist," Mrs. Clinton said, referring to Mr. Stephanopoulos, who looked slightly uncomfortable.

While gaining in the polls, Mrs. Clinton still remains behind in both the total popular vote and the pledged delegate count, but vowed again she would remain in the race until the primary season ends in early June.

Mr. Obama has continued to gain ground in endorsements by superdelegates -- party insiders and elected officials who aren't required to support any candidate until the party's convention. The Illinois senator now has 253 superdelegates compared with Mrs. Clinton's 274, with 268 uncommitted, but leads her in pledged delegates, 1,492 to her 1,338.

Asked by Mr. Stephanopoulos if a decision in her favor by the superdelegates would "overturn the will of the pledged delegates" and create an "irreparable breach" in the African-American community, she countered that she was ahead in the popular vote -- if results from the Florida and Michigan primaries were included.

Those two states were disqualified by the Democratic National Committee for ignoring party rules and holding their primaries ahead of schedule. Neither candidates campaigned in Florida and Mr. Obama's name wasn't on the ballot in Michigan, but "that was his choice," Mrs. Clinton claimed.

"The rules said we shouldn't campaign," she said. "But there was nothing saying take your name off the ballot, and there was nothing saying that, eventually, we wouldn't give the voters, 2.3 million of them, in Florida and Michigan, 2.3 million of them, a chance to participate in the process."

"That is the process. We're going through this campaign, and when the process finishes, the [superdelegates] can look at the factors and decide who is the strongest candidate."

She stressed, however, as she has repeatedly, that if Mr. Obama is the nominee, "I will work my heart out for him, and he has said he will do the same for me."