Bill Richardson, the former New Mexico governor who held in two senior positions in President Bill Clinton's administration, was labeled a turncoat in 2008 for endorsing Barack Obama over Hillary Rodham Clinton.

In 2008, Bill Richardson endorses Barack Obama (AP Photo/Alex Brandon) Bill Richardson endorses Barack Obama in 2008. (Alex Brandon/AP)

Now, as Clinton weighs a second presidential run in 2016, Richardson wants the political world to know he's not on board -- yet.

When I called Richardson last week soliciting his thoughts on Clinton's book tour, the first thing Richardson said was, "You know I'm not in the 'Ready for Hillary' camp, right?"

Why not?

"It's because of our differences when I endorsed Obama," Richardson said. "The differences haven't healed, and I'm not in the suck-up camp."

To call them differences is putting it mildly. Richardson infuriated both Clintons and their network of longtime supporters with what they saw as disloyalty.

From the moment Richardson gave up his own presidential campaign after losses in the early 2008 primaries, Bill and Hillary Clinton began an intensive courtship of their old friend. Both Clintons called regularly. Bill Clinton even flew to New Mexico to watch the Super Bowl with Richardson at the governor's mansion in Santa Fe -- and Richardson invited news photographers in to document it all.

But in March 2008, with Clinton lagging behind Obama in the nomination fight, Richardson broke with the Clintons and endorsed Obama. James Carville, a longtime Clinton adviser, had particularly scathing words, calling Richardson Judas Iscariot.

Bill Richardson at the New Mexico governor's mansion in 2009 (By Craig Fritz for The Washington Post) Bill Richardson at the New Mexico governor's mansion in 2009 (By Craig Fritz for The Washington Post)

Richardson, who in the mid-2000s was the Democratic Party's highest-profile Hispanic official, is out of office now and has no plans to run for president again. But he's been keeping a close eye on Clinton this month as she's promoting her book, "Hard Choices."

"As much as I say to you that I'm not in her camp, I haven't signed on, I believe this little listening book tour has been a stroke of genius," Richardson said. "What she's doing is she's becoming unstoppable. One, she's whetting the appetite of every Democrat, particularly women that are going to vote for her in droves for historical reasons. Two, she's putting out all the baggage early and I think dealing with it effectively. Third, she's recruiting every able campaign worker, especially the Obama team, which is unsurpassed in their skills for electioneering. And then fourth, she's honing her skills."

Richardson said he was in the audience when Clinton spoke in New York on June 12 at a fundraising luncheon for the World Resources Institute.

"I must say, her speech and delivery were very good, very strong," Richardson said. "So I think this period of the book tour, the speech-making is an actual campaign. I have no doubt that she will run."

Asked whether Clinton's stumbles in talking about her wealth will prove damaging, Richardson said it will be only "a minor problem."

"I am sure some Democrat will run from her left and call her a Wall Street, pro-business candidate, but it won't be sufficient to derail her," Richardson said. "I think in the general election, it might be an asset that she's more moderate and pro-business. She's not ostentatious about her lifestyle."

So what then is Clinton's greatest obstacle?

"Her vulnerability is the inevitability syndrome," Richardson said. "She's got to be hustling and she's got to go to every nook and cranny and go to every event."

But, he added, "She's got the eye of the tiger."