THE KILLIAN FILE. When I first heard last night about the blogland chatter that CBS News had relied on forged documents in its 60 Minutes report on George W. Bush's National Guard service, my instinct was dismiss it. Not that the media aren't capable of monumental screw-ups. But when CBS said it had consulted experts, I assumed that meant it had showed the documents to people who make their living knowing about the history of typewriters, fonts, and the like.

Now it looks as bad as it can get for CBS. The Washington Post and the New York Times are both reporting that experts they approached believe the documents bear numerous hallmarks of having been produced many years after 1972 and '73, when they were supposedly typed by the late lieutenant colonel Jerry Killian.

No, it hasn't been definitively proved that the documents were forged. But it appears far more likely that they were banged out on a computer using Microsoft Word than on a typewriter at a military basis more than 30 years ago.

For CBS, we're talking humiliation, resignations, plague, locusts, and seven years of bad luck. For the Kerry campaign, we're talking about an absolute nightmare.

The Times report seems to offer at least some possibility that the documents are authentic. But it strikes me that this is one of those things where the only possible exculpatory explanation would be a rather simple one, the sort of thing that CBS could put out today - indeed, should have put out already. Instead, network execs appear to have gone into the bunker, insisting that the documents are genuine without offering any real proof.

Drudge claims a source told him that "CBSNEWS anchor and 60 MINUTES correspondent Dan Rather [was] privately 'shell-shocked' by the increasing likelihood that the documents in question were fraudulent." Well, I don't have much doubt about that.

For the Kerry campaign, it gets worse - much worse. Glenn Reynolds reproduces this from "The Prowler," on the American Spectator's website, which I can't access right now because of the heavy traffic:

More than six weeks ago, an opposition research staffer for the Democratic National Committee received documents purportedly written by President George W. Bush's Texas Air National Guard squadron commander, the late Col. Jerry Killian....

A CBS producer, who initially tipped off The Prowler about the 60 Minutes story, says that despite seeking professional assurances that the documents were legitimate, there was uncertainty even among the group of producers and researchers working on the story.

"The problem was we had one set of documents from Bush's file that had Killian calling Bush 'an exceptionally fine young officer and pilot.' And someone who Killian said 'performed in an outstanding manner.' Then you have these new documents and the tone and content are so different."

The CBS producer said that some alarms bells went off last week when the signatures and initials of Killian on the documents in hand did not match up with other documents available on the public record, but producers chose to move ahead with the story. "This was too hot not to push. If there were doubts, those people didn't show it," says the producer, who works on a rival CBS News program.

Reynolds notes that there's also some buzz that it's all a Karl Rove set-up. But that seems too clever by many halves.

None of this refutes the basic accusations against Bush - that he got into the National Guard through family connections in order to avoid combat duty in Vietnam, and that no one can recall his ever having popped up in Alabama. The Boston Globe's report earlier this week - that Bush failed to sign up with a Boston-area Guard unit, as he was obligated to do, while he was attending Harvard Business School - seems solid. But none of that's going to matter if CBS can't authenticate the documents in a way that we'll all find believable.

Josh Marshall is in wait-and-see mode, which seems smart. So am I - although, frankly, it's difficult to picture this having a happy ending for either CBS News or Kerry. Especially if it turns out that the documents came from someone aligned with his campaign.