WASHINGTON - Democratic presidential candidate Barack Obama on Sunday brushed aside a challenge from Hillary Rodham Clinton to debate before the May 6 primaries in Indiana and North Carolina.
On Saturday, Clinton said she wants Obama to face off with her in a debate without a moderator, Lincoln-Douglas style.
"I'm not ducking. We've had 21" debates, Obama said on "Fox News Sunday."
"For two weeks, two big states, we want to make sure we're talking to as many voters on the ground, taking questions from voters," he said. "We're not going to have debates between now and Indiana."
The more open style of debating where each side presents an argument gets its name from the famed debates that took place during the 1858 U.S. Senate race in Illinois between Republican Abraham Lincoln and Democrat Stephen Douglas.
Trailing in delegates and the popular vote, Clinton has been stepping up the pressure on Obama for more debates in advance of primaries on May 6 in Indiana and North Carolina.
Obama was planning to return to his home in Chicago on Sunday and had no public events scheduled. Clinton was spending the day campaigning in North Carolina.
Democratic National Committee Chairman Howard Dean said superdelegates should make known their choices on the Democratic nominee for president by the end of June. Ultimately, he said he believes their decisions will be based on who is more electable, rather than necessarily who has the most pledged delegates, because that is what party rules stipulate.
"This is essentially pretty close to a tie here," Dean said on NBC's "Meet the Press."
"What's going to happen in the last nine primaries is there's going to be some feeling at some point that one of these candidates is more likely to win than the other and that person will get the nomination. I can't tell you who that is, I have no idea who that is, but that's what's going to happen," Dean said.
Dean also said he expected the party to heal from the bitter primary race if superdelegates make their decisions in June and that he believes Michigan and Florida delegates will be "seated in some way."
"If you go into the convention divided, it's pretty likely you'll come out of the convention divided," he said.
The Democratic Party stepped up its attack on Sen. John McCain, using a new party ad to cast the presumed Republican presidential nominee as a commander in chief who would keep troops in Iraq for 100 years. The ad is part of a half-million-dollar, three-week national cable television campaign aimed at linking the Arizona senator to the policies of President Bush.
The ad set to begin airing Monday accuses McCain of wanting to remain in Iraq for "maybe 100" years, a link to a remark McCain made in January while campaigning in New Hampshire. The ad concludes, "If all he offers is more of the same is John McCain the right choice for America's future?"
Since then, McCain has repeatedly said he has no intention of extending the war into the next century, but would keep a U.S. military presence in Iraq much as the United States has in Germany, Japan and South Korea.
The Democratic candidates have also acknowledged they would keep non-combat troops in Iraq to ensure its stability. But they have said they would begin withdrawing combat troops promptly upon becoming president, a step McCain has said would be precipitous.
The DNC has been organizing a drumbeat against McCain at the state party level to coincide with McCain's travels across the country.
Meanwhile, Obama has become a Republican target. The North Carolina Republican Party aired an ad, over McCain's objections, that uses remarks by Obama's former pastor to portray Obama as too extreme. The ad points out that the two Democrats running for state governor have endorsed the Illinois senator.
Freedom's Watch, a conservative group, and the National Republican Congressional Committee are running ads in Louisiana criticizing Obama's health care proposal and linking him to a Louisiana congressional candidate.