The folks at President Obama's Chicago campaign headquarters must have breathed several sighs of relief Thursday afternoon: Former Pennsylvania Gov. Ed Rendell, a frequent critic of the president’s reelection strategy, was on MSNBC, where he’s a paid commentator, heaping unadulterated praise on Obama’s big economic speech in Cleveland.

“I may be their least favorite Democrat,” Rendell says about the Obama campaign, “but I’ll probably do better work for them on TV than almost anybody because I don’t say that our guy’s an angel and their guy’s a devil. Chicago doesn’t understand that. They want you to be not reasonable.”

The 68-year-old Rendell, who retired from politics in 2011 to advise an investment bank and try his hand at high-tech venture capitalism, has just published A Nation of Wusses, part memoir of his colorful career in elective office (as district attorney, mayor of Philadelphia and two-term governor) and part manifesto demanding that our public officials show some cojones from time to time.

“I am always reasonable,” he tells me. “I admit when we make mistakes. That gives me greater credibility when I say you should vote for our guy.” He adds with a snort: “You won’t see me doing any hostage videos.”

Rendell, who fervently supported Hillary Clinton for president in 2008 and would love to see her run again in 2016 (“so I can be her campaign manager,” he likes to joke), claims he’s just as eager this time around to see Obama get  a second term. But that hasn’t stopped him from slamming a recent Obama television spot attacking Mitt Romney’s leveraged buyout firm, Bain Capital.

“Does anybody believe that the first Bain ad, which called Romney a vampire, wasn’t over the top and wrong?” he asks. “I’ve made a very strong case that Obama had every right to examine Romney’s record at Bain. But I just thought the language and the tone of that ad was disappointing—and I stand by that.”

He likewise declines to disavow a quip, made while attending a Boston Celtics game with his fellow governor, Romney, in 2005: “This will be the kiss of death, but if I had to choose the next Republican president, if there’s going to be one it would be Governor Romney.”

“Of all the Republicans that sought the presidency, Governor Romney is by far the best,” Rendell explains. “I’m happy that he’s the nominee, in case the Republicans win. I’d rather it be the sanest of their candidates.” Rendell is quick to add, of course, that Obama is a better candidate in terms of leadership ability and policies.

Nor does he shrink from taking potshots, during his regular cable appearances, at various alleged miscues at the White House and the campaign.

“I’m not a surrogate, I’m an advocate,” says Rendell, who nonetheless plans to take part in a pro-Obama campaign event Saturday near Allentown, Pa. “I reserve the right to do analysis and comment…Chicago tells me when they’re concerned about something I said, and I respond and tell them why I said it. They say, ‘What you said can be misinterpreted,’ etc., etc., and I say that by not being a 100-percent shill I am building up my credibility with those undecided independent voters who don’t believe that our guy’s an angel and their guy’s the devil and don’t like to be talked to that way.”

Rendell adds with a laugh: “Look, if they [the Obama campaign believe that I have warts, then they’re going to have to take me warts and all.”

Rendell seems resigned to his role as a professional kibitzer, though he frankly admits to missing the game. “Very much so,” he says. “My life is interesting and rewarding, but if you asked Michael Jordan, ‘Do you miss playing basketball,’ he’d tell you in a New York minute that the answer is yes.”

Rendell’s book, which is subtitled How America's Leaders Lost the Guts to Make Us Great, argues that political cowardice—including what Democrats and Republicans alike see as the need to pander to their extreme bases in order to keep their jobs—is ruining the country.

“We’re stagnating as a country and paralyzed, in part because of the polarization everyone talks about, but in part because we’ve got leaders and elected officials both in state capitals and in Washington who are afraid to tell people the truth,” Rendell says. “They’re afraid to take the slightest risk that might cause them to lose their jobs and as a result nothing gets done, because Democrats are afraid to do anything to offend their base and Republicans are afraid to do anything to offend their base—even though it is right, and even though it is necessary.”

Ironically, Rendell says, political courage is rewarded more often than not. He cites his own experience of raising taxes early in his first term as governor in order to meet a budget shortfall. During his reelection campaign, he says, his opponent spent $15 million running ads attacking him for raising taxes—and Rendell won by a 21-point landslide.

“The people have to give their elected officials a permission slip to say it’s OK to raise revenue when we have to,” Rendell says. “It’s OK. We’re not stupid. We know we can’t get out of this mess without raising revenue—and, for Democrats, without cutting spending and changing some of the entitlement programs. So I want to tell people that nothing is going to change unless they actively reach out to their elected officials and say, look, we’re not dumb. We understand. And, unlike what Jack Nicholson said, we can handle the truth.”

While Rendell has faulted Obama for refusing to embrace the entitlement-reforming, revenue-raising fiscal program presented by the Simpson-Bowles deficit reduction commission—a notable example of wussing out—he praises the president for attempting to strike the so-called “grand bargain” with Republican House Speaker John Boehner during last summer’s debt ceiling debate.

“When he was close to doing the big deal with Boehner, that was essentially modeled on Simpson-Bowles,” he says. “You couldn’t cut the deficit by five trillion dollars without doing a lot of what Simpson-Bowles calls for. It’s fair to say he made a real effort to enact it into law.”

Alas, Boehner bailed on the agreement when Tea Party members of his conference vociferously rebelled.

Rendell says he personally likes the president, who is often portrayed as insular and remote with his fellow Democratic politicians. “We have a good relationship. I wouldn’t say we are close friends,”  Rendell says. “I just know that when he’s with you, he can be very charming and very funny. He’s a nice guy to be around.”

Romney, of course, is likable enough himself, though Rendell says he hasn’t a clue what sort of president his former colleague would be.

“That would be determined by whether Governor Romney would be his own person or let the base of his party dominate his decision-making,” Rendell says. “If he lets the base of his party dominate his decision-making, we’d have a very divided country with groups pitted against each other and an economy that would widen the gap between the very rich and the rest of us. I don’t think that would be good for America.”