Obama takes aim at McCain on Iraq

"For him to argue that -- which he has repeatedly -- that any suggestion that we withdraw troops is surrender, that implies that, you know, we will be there as long as he thinks it’s necessary for us to be there," he said.

Obama and Clinton were both on the campaign trail in Pennsylvania, site of the next contest in their hard-fought battle. Both accused McCain of lacking a clear plan to end turmoil in U.S. housing markets.

"Senator McCain recently gave a speech on the economy, and best I could determine his plan was not to have a plan," Clinton, a New York senator, said during an economic round-table in Harrisburg.

Clinton, who trails Obama in pledged delegates won in state-by-state contests, has rejected calls to step aside in the Democratic race.

Neither candidate is likely to have the 2,024 delegates needed to win the nomination after the contests end in early June, leaving the decision up to nearly 800 superdelegates -- elected officials and party insiders who are free to back any candidate.

OBAMA GETS ANOTHER ENDORSEMENT

Obama on Monday picked up the support of another superdelegate, Minnesota Sen. Amy Klobuchar, who said Clinton had the right to continue campaigning and she believed the party would eventually rally around the winner.

"I have faith that our candidates will figure this out and that this will come to a conclusion in early summer," she told reporters. "I believe that they’ll do the right thing and will figure this out."

McCain, a military veteran and former prisoner of war in Vietnam, kicked off a weeklong tour in Mississippi highlighting his military service and introducing his life story to U.S. voters.

Obama said McCain deserved praise for having "sacrificed on behalf of his country." But he said the Republican senator’s stance on Iraq and his support for preserving the Bush tax cuts for the wealthy showed he would continue the current president’s policies.

"He is clinging to the policies of the past and we are already in the future," Obama told a rally in Allentown.

McCain has criticized Obama and Clinton for proposing a quick U.S. withdrawal from Iraq, saying that would embolden U.S. enemies and lead to greater chaos in the Middle East.

Obama defended his frequent criticism of McCain for saying at a campaign event in January he would be willing to leave U.S. troops in Iraq for 100 years. McCain says the comment referred to a prolonged U.S. troop presence similar to the presence in Japan and South Korea, not a combat presence.

"We’ve been in South Korea for 50 years. And he’s used that as an example, as George Bush has, and that is decades," Obama said. "That’s something that the United States can’t afford, and I think that’s going to be a debate that we’re going to have in the general election, should I be the nominee."

McCain’s campaign said it was pleased Obama had at least acknowledged the Arizona senator was referring to a South Korea-like peacetime military presence in Iraq.

"With Barack Obama finally acknowledging today John McCain does not support a 100-year war in Iraq, we expect that he will answer his own calls for a more honest debate and stop playing crude politics with such an important issue," McCain spokesman Tucker Bounds said.

(Additional reporting by Ellen Wulfhorst and Steve Holland; writing by John Whitesides; editing by Mohammad Zargham)

(To read more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at http:blogs.reuters.com/trail08/)