Edwards had to quit the race because the affair was being televised on every major-network for weeks.
Our current little fiasco with the Governor of South Carolina is not only because he was a primary suspect for a G.O.P candidate, but that the news networks are patting them selves on the back for being correctly suspecting.
The day before the big news release that he was banging some Argentinean the networks had him in the headlines. They knew that it was either going to turn out to be that he was dead, on the Appalachian Trails, or in some sort of scandal.
The networks look to make mad-bank off of the misfortunes of others. The only bias (for the networks) depends on the crowd they are catering to.