ONCE AGAIN, it seems, Gov. Rendell opened his mouth and truth fell out.

And once again, he's being chided for being sexist and impolitic.

Excuse me, but - this is news?

The only difference this time is that Rendell made imprudent remarks during a private conversation that were picked up by an open microphone. Usually, he makes them deliberately and publicly.

In case you've been in a coma, here's what happened:

Tuesday, during a break at the National Governors Association meeting in Philadelphia, Rendell was standing at a lectern, where the microphone was on, apparently unbeknownst to him.

In a private conversation about President-elect Barack Obama's appointment of Arizona Gov. Janet Napolitano as chief of Homeland Security, he said:

"Janet's perfect for the job and for that job you have to have no life. Janet has no family. Perfect. She can devote, literally, 19, 20 hours a day to it."

CNN reported the remarks, and then Campbell Brown, one of its star political anchors, teed off on Rendell.

"If a man had been Obama's choice for the job, would having a family or not having a family ever even have been an issue?" Brown said.

"I know what you meant to say," she added, "but your comments do perpetuate stereotypes that put us in boxes, both mothers and single women."

Brown also commented on Rendell's bizarre assumption that not having a family means you have "no life."

What he meant, of course, is that no one would be home at night, waiting for dinner, a diaper change or directions for making a diorama, so Napolitano could work, guilt-free, around the clock.

The story unleashed TV punditizing and provoked a New York Times column yesterday by Gail Collins.

What to make of it?

I didn't trust my own lack of pique so I called the sentries who guard the feminist ramparts full time.

Karen Bojar, head of the Philadelphia chapter of the National Organization for Women, said that Rendell's comments about Napolitano are "offensive on two fronts."

"He implies that people without partners and children don't have a life. How does he know? She could have a very rich social network, deep ties with extended family, etc.," Bojar said in an e-mail.

"He implies that having a family is a disqualifier for a high powered job - something never said about a man."

But Bojar didn't seem particularly incensed, either.

"That said, I believe Rendell does respect the strong women he's worked with and I don't think he's some Neanderthal. However, he's a guy in his mid-60s and grew up at a time when sexism was the norm. Old habits of thinking die hard."

Carol Tracy, of the Women's Law Project, said the remark was typical of Rendell.

"It's always a double-edged sword with the governor. It was both insensitive and there's underlying truth to it.

"An important issue that weighs far more heavily on women than men is the impact of family responsibilities in the workplace," Tracy said.

"We don't talk about it enough. It has limited opportunities for women; it has limited the contributions that many women can make to government, to business, because our employment practices are so hostile to working families."

In other words, we should be talking about the issue, not the fact that Rendell is afflicted with Political Tourette's Syndrome: Every now and then, he blurts out an uncomfortable truth.

That propensity, of course, is what differentiates him from the pols who never violate the stifling boundaries of political correctness, and mouth only platitudes and party-approved piffle.

We say we  hate that about politicians, and then we assault Rendell for occasionally treading on the tender turf of truth.

He was chastised, for instance, for the comment he made during the Obama-Clinton primary that some Pennsylvanians weren't ready to vote for an African- American for president.

Whatever his motives - he was supporting Hillary Clinton - that was true.

The open microphone on Tuesday apparently also caught Rendell saying of Sarah Palin:

She's "not a genius, but she has very good political instincts," he said, according to a political Web site.

And that's, unfortunately, true, too. *

E-mail porterj@phillynews.com or call 215-854-5850.

For recent columns: http://go.philly.com/porter