"Even though I disagree with him, Joe Lieberman is well within his right to vote against a public option," Dean said. "No one has the right to oppose the leader. That isn't fair."
Dean predicted Senate Majority Leader Harry Reid will be able to reach an understanding with moderate senators such as Blanche Lincoln (D-AR) and Ben Nelson (D-NE).
"They honor this stuff, it's the unspoken rule," he said.
Dean said he doesn't envy Reid, who has a much more difficult job than Speaker Nancy Pelosi in getting his members in line. He said he supports using reconciliation as a tactic of getting a final bill passed if necessary.
Dean, a medical doctor who served as governor of Vermont, said he hasn't wavered on whether a public option should be part of the health care plan.
"If we don't have a public option this is not health care reform, period," he said. "If it were me writing the bill the public option would be a lot stronger, but this is workable what you've got here."
He thinks the final bill will have a public option, but if it doesn't, he warned the Democrats risk losing their majority in 2010. He said if that happens activists would feel disillusioned and turnout would be low.
"If they don't pass a strong health care bill with a decent public option I think we could lose the majority in the house. Their fate is tied to the health care bill," he said.
"If the activists sit on their hands next year they are going down and we could lose 30 or 40 seats," Dean said.