Sources with direct knowledge of the conversation between Sen. Clinton and Gov. Bill Richardson, D-N.M., prior to the Governor's endorsement of Obama say she told him flatly, "He cannot win, Bill. He cannot win."

Richardson, who served in President Clinton's cabinet, disagreed.

At a rally in Oregon, standing next to Obama, Richardson insisted, "My great affection and admiration for Hillary Clinton and President Bill Clinton will never waver." But he added, "It is time, however, for Democrats to stop fighting among ourselves and to prepare for the tough fight we will face against John McCain in the fall."