Howard Dean (search) says he was only having some fun when he described the centrist Democratic Leadership Council (search) as the "Republican" part of the Democratic Party. But Joe Lieberman (search), a former chairman of the group, says he did not see anything to laugh about.

"Does he realize when he's saying that he's pushing Bill Clinton, a hundred members of Congress, countless governors and mayors around America, state officials, who are members of the DLC and the new Democratic movement out of the Democratic Party?" Lieberman told reporters Tuesday in Manchester.

"Howard Dean thinks he can conquer by dividing, but the truth is, in politics you win by uniting," he said.

Dean's comment about the DLC came during a town meeting in Exeter on Monday. The organization, which espouses a middle-of-the-road philosophy, has criticized the former Vermont governor as being too liberal.

Dean, who visited an auto parts manufacturer Tuesday in Seabrook, did not specifically address Lieberman's comments.

Asked whether he was joking about the "Republican" comment, Dean said: "I was having a little fun at their expense. They've been having eight months of fun at my expense."

Lieberman responded: "He's a candidate for president of the United States, he's a candidate for commander in chief of the armed forces. This is just one of a series of what I would call impulsive, ill-advised and sometimes irresponsible statements Howard Dean has made.

"I love to joke, but people can tell when I'm joking," Lieberman said.

The DLC wasn't amused, either.

"It's a cheap shot not just at us, but at former DLC chairmen like Bill Clinton, Dick Gephardt, and Joe Lieberman, along with hundreds of hard-working Democratic elected officials around the country who are part of our movement," a statement on the council's Web site said Tuesday. "It also illustrates why we've worried about Dean's loose-lipped approach all along."