"It was one of the worst political meetings I have ever attended," one superdelegate said.

According to those at the meeting, Clinton - who flew in from Chicago with bags under his eyes - was classic old Bill at first, charming and making small talk with the 15 or so delegates who gathered in a room behind the convention stage.

But as the group moved together for the perfunctory photo, Rachel Binah, a former Richardson delegate who now supports Hillary Clinton, told Bill how "sorry" she was to have heard former Clinton campaign manager James Carville call Richardson a "Judas" for backing Obama.

It was as if someone pulled the pin from a grenade.

"Five times to my face (Richardson) said that he would never do that," a red-faced, finger-pointing Clinton erupted.

The former president then went on a tirade that ran from the media's unfair treatment of Hillary to questions about the fairness of the votes in state caucuses that voted for Obama. It ended with him asking delegates to imagine what the reaction would be if Obama was trailing by just 1 percent and people were telling him to drop out.

"It was very, very intense," said one attendee. "Not at all like the Bill of earlier campaigns."

When he finally wound down, Bill was asked what message he wanted the delegates to take away from the meeting.

At that point, a much calmer Clinton outlined his message of party unity.

"It was kind of strange later when he took the stage and told everyone to 'chill out,' " one delegate told us.

"We couldn't help but think he was also talking to himself."