James Carville told the New York Times that Richardson, a former member of Bill Clinton's Cabinet, had committed "an act of betrayal," adding that it "came right around the anniversary of the day when Judas sold out [Jesus] for 30 pieces of silver, so I think the timing is appropriate, if ironic."

"I'm not going to get in the gutter like that," Richardson responded on "Fox News Sunday." "And you know, that's typical of many of the people around Senator Clinton. They think they have a sense of entitlement to the presidency."

"I am very loyal to the Clintons," said Richardson, but he said he wanted something beyond "Bush, Clinton, Bush, Clinton." "You know, what about the rest of us?" he asked.

He called for "a new generation of leadership," and added, "I think Obama represents this new change of not just bipartisanship, but bringing people together, bringing races together, bringing America's role in the world to be respected again."