Last August, Jane Mayer wrote a long investigative article in The New Yorker about the Koch brothers, the conservative billionaires who bankroll a host of right-wing causes. Since then, she's apparently become the victim of a disturbing, organized smear campaign.

Mayer, who's reported extensively on America's use of torture during the "War on Terror" and co-authored books on Clarence Thomas and Ronald Reagan, is certainly no stranger to peals of right-wing outrage. But her work on the reclusive Koch brothers (whose official objections to the story are laid out in this letter) seems to have raised it to a new level. Sources tell us that rumors have been circulating for some time now that a private investigator was hired to dig up dirt on Mayer in the wake of the Koch brothers story. (Dirty business, but that sort of thing does happen.)

Nothing's been confirmed so far. But the circumstantial evidence does seem indicate that someone out there is planting (weak) negative stories about Mayer with any news outlet who might take them. There have been at least three efforts so far:

The Washington Examiner (which editorialized extensively against Mayer's Koch brothers piece) did research trying to turn up evidence of Mayer's political partisanship; they apparently didn't find anything worth reporting.

Elaine Lafferty wrote a pro-Koch response to Mayer's story in The Daily Beast, complete with friendly quotes from David Koch—who was unwilling to speak with Mayer herself. TDB later added an editor's note to the story admitting, among other things, that they "should have noted that the writer who interviewed Koch had been a consultant for the McCain/Palin campaign."

And today, Keith Kelly reportson a third incident: The Daily Caller spent "several weeks" investigating a story that Mayer plagiarized work in her Koch brothers article, and in another story years ago. They found no evidence, and now they've dropped the story.

"Who is behind the apparently concerted campaign to smear The New Yorker's Jane Mayer?" Kelly asks, rhetorically. It doesn't take a great investigative journalist to draw up a short list of prime suspects. Scrutiny of reporters' work is fine, but hiring P.I.'s for political-style opposition research and trying to plant false stories is a mark of unscrupulous desperation. After three whiffs, will any more media outlets take the bait against Mayer? We'll be watching!

Any reporters out there know more about the smear campaign against Jane Mayer? Email me. Anonymity guaranteed.

[Photo of David Koch via Getty. Photo of Mayer via Wikipedia]