In polite but direct remarks, Senator Barack Obama of Illinois took on the Clintons over Iraq this morning, delivering the sort of punch that might always tempt the famous bare knuckles of Clinton operatives. But, by mid-afternoon today, the Clinton camp was responding coolly.

On MSNBC this morning, Mr. Obama had this exchange with reporter David Gregory:

Mr. Gregory: “Bill Clinton has been interviewed the last couple of days about his global warming initiative, and one of the things he said last night is that there really isn’t any difference between you and Senator Clinton in terms of your voting records on Iraq. Do you think that is about right?”

Mr. Obama: “Well, I suppose that’s true if you leave out the fact that she authorized it and supported it and I said it was a bad idea. You know, that’s a fairly major difference.”

Mr. Gregory: “And to you, I gather this becomes a fundamental question of judgment, does it not?”

Mr. Obama: “Well, it does. I think very highly of Senator Clinton. I think she is a wonderful senator from New York, but — and I think very highly of Bill Clinton, but I think that it is fair to say that we had a fundamentally different opinion on the wisdom of this war. And I don’t think we can revise history when it comes to that.”

Mr. Obama has repeatedly made the point that he opposed the Iraq war as far back as the fall of 2002, when Mrs. Clinton was voting in the Senate to authorize military action in Iraq. But, until his remarks this morning, Mr. Obama has not been quite so direct in challenging President Clinton’s assertion — made mostly at private fundraisers this spring — that Mr. Obama and Mrs. Clinton have the same fundamental positions on Iraq today.

Mr. Obama’s initial response to Mr. Gregory’s first question was also interesting, in that Mr. Obama acknowledged that he and Mrs. Clinton had roughly similar voting records on Iraq in the Senate. (Then, of course, Mr. Obama got to the meat of the matter for many Democrats — where the two candidates stood on the war in 2002 and 2003, when it arguably mattered more).

The Clinton camp, meanwhile, has not pounced on Mr. Obama’s latest remarks — a noteworthy choice, given that some of her supporters worry that her campaign overreacts to the Obama threat at times.

Asked about Mr. Obama’s comments, all that Mrs. Clinton’s communications director, Howard Wolfson, would say was, “Senator Clinton is focused on uniting Democrats and ending the war.”