ESPN has unleashed a minor storm with “Bonds on Bonds,” a new “reality” show chronicling slugger Barry Bonds’ assault on baseball’s home run record. Even some staffers complained, expressing skepticism that the sports net can cover Bonds while it’s in bed with him.

“Are the best interests of journalism being served when … ESPN trades on its ability to credibly cover the Bonds story by paying for the dubious privilege of allowing Bonds to put his own spin on that story?” Los Angeles Times columnist Mike Penner asked.

To which we say, “So what else is new?”

Figures from sports, politics and to a growing degree law all freely flit from playing the game to being paid to opine about it. Coaches and players head from the sideline directly into the broadcast booth. Politicians and trial attorneys rotate from being “in” to “out” by parking themselves on news programs, as lawyers including Nancy Grace and Greta Van Susteren have left the courtroom to embark on new careers as crusading hosts.

The political roll call is especially long, from Pat Buchanan appearing on “Crossfire” between presidential runs to Joe Scarborough and George Stephanopoulos’ TV careers, which took, and Susan Molinari’s, which didn’t.

Indeed, Molinari’s switch in 1997 — leaving Congress to host a CBS News program — triggered massive hand-wringing about the TV-politics “revolving door.” As American Journalism Review’s Rem Rieder wondered at the time, “What does this say about the credentials required to work in television? Can anyone just walk in off the street and suit up?”

Pretty much, yeah.

Of course, all this insider knowledge comes with a price. For starters, athletes, coaches and politicians don’t come to these new roles with a journalist’s objectivity; rather, they often harbor an agenda and are prone to defend former colleagues. Some athletes-turned-broadcasters, for example, were unwilling to criticize NBA star Ron Artest after he began a melee during a Detroit-Indiana game by diving into the crowd to pursue a beer-throwing fan.

Moreover, there’s always the threat that transplanted pundits may jump back to their old spheres, meaning Fox News analyst Newt Gingrich needs to watch what he says lest it complicate his possible presidential bid in 2008.

Despite similarities with sports and politics, in fact, this is one area where Hollywood parts company. Showbiz insiders don’t generally have the option of parachuting from, say, running Fox to opining about it on “Entertainment Tonight,” which partially explains the “Huh?” reaction to former Disney CEO Michael Eisner’s CNBC chat show. Had Eisner gone from coaching the Mighty Ducks or Angels to an in-studio role at ESPN, such a move wouldn’t have raised so much as an eyebrow.

So, yes, ESPN has unquestionably compromised some of its credibility by aligning itself with Bonds to juice ratings.

On the plus side, the truth is that ESPN didn’t have that much credibility to lose.

Totally Loony Channel: Speaking of squandered credibility, the network formerly known as the Learning Channel, TLC, lurches into high camp with a made-over lineup punctuated by the April 10 premieres of “Shalom in the Home” and “Honey, We’re Killing the Kids.”

Both series are predicated on families in turmoil, featuring glib experts — a rabbi and nutritionist, respectively — who first lay a guilt trip on the parents for screwing up their children, then endeavor to set the families onto a healthier track.

Although couched as self-help, it’s really just “Jerry Springer” in new wardrobe and about as cynical as programming gets — although absurd enough to be unintentionally comic for those able to hold down dinner watching it.

The nutritionist can probably assist with that part, but those responsible for the shows should really consult with the rabbi.

As for TLC’s reputation, say “shalom.”