Obama has cultivated an image of being above the fray, and his criticism of Clinton usually comes in the form of a response to her charges. But he's not above upping the ante, as he did Friday during a stop in Milwaukee.
During a news conference, he was asked about Clinton's accusation that he watered down a bill regulating the nuclear industry. He pointed out that Clinton is criticizing him for a bill she voted for and touted on her Web site.
"I understand that Senator Clinton, periodically when she's feeling down, launches attacks as a way of trying to boost her appeal," he told reporters.
At a subsequent rally at the downtown Midwest Airlines Center, Obama brought up her latest criticism of him as someone who gives a good speech but doesn't have much action to show for it. Clinton told voters in Cincinnati Friday, "This primary election offers a very big choice to the voters of Ohio. You can choose speeches or solutions."
"She's right," Obama said in Milwaukee. "Speeches alone don't do anything. But you know what, neither do negative attacks."