Fargo, N.D. ? Democrat Barack Obama struggled Thursday to explain how his upcoming trip to Iraq might refine, but not basically alter, his promise to quickly remove U.S. combat troops from the war.

A dustup over war policy – one of the main issues separating the Illinois senator from his Republican opponent, John McCain – overshadowed Obama’s town-hall meeting here with veterans to talk about patriotism and his plans to care for them. Republicans pounced on the chance to characterize Obama as altering one of the core policies that drove his candidacy “for the sake of political expedience.” He denied equally forcefully that he was shifting positions.

Arriving in Fargo, Obama hastily called a news conference to discuss news of a sixth straight month of nationwide job losses, but the questioning turned to Iraq policy and his impending trip there.

“I am going to do a thorough assessment when I’m there,” he said. “I’m sure I’ll have more information and continue to refine my policy.”

He left the impression that his talks with military commanders there could refine his promise to remove U.S. combat troops within 16 months of taking office.

Less than four hours later, after the town hall meeting, Obama appeared before reporters for another statement and round of questions to “try this again.”

“Apparently I was not clear enough this morning,” he said. He blamed any confusion on the McCain campaign, which he said had “primed the pump with the press” to suggest “we were changing our policy when we haven’t.”

“I have said throughout this campaign that this war was ill-conceived, that it was a strategic blunder and that it needs to come to an end,” he said. “I have also said I would be deliberate and careful about how we get out. That position has not changed. I am not searching for maneuvering room with respect to that position.”