"So why did so much of the mainstream media so assiduously follow the tabloid lead on the Tiger Woods story?"

That's the question raised by Paul Farhi for the American Journalism Review.

Perhaps because of the way another recent sex scandal played out. In 2007, the National Enquirer reported that former Sen. John Edwards had had an affair with a videographer who worked on his presidential campaign, Rielle Hunter, and had fathered her baby. Edwards repeatedly denied the allegation, dismissing the story as "tabloid trash."

And...

What changed between the Edwards and Woods stories? NPR's Shepard suggests the first scandal incited the firestorm over the second: "The John Edwards story forced legitimate news organizations not to ignore Tiger Woods. The mainstream media used to dismiss that kind of story. Now they do so at their own peril. The floodgates are open. Anything goes."