If you want to see a perfect example of the media's decided-upon narrative shaping election coverage, look no further than Hillary Clinton's story about landing under sniper fire in Bosnia in 1996. From the Saturday WaPo (page A05):
Hillary Clinton has been regaling supporters on the campaign trail with hair-raising tales of a trip she made to Bosnia in March 1996. In her retelling, she was sent to places that her husband, President Bill Clinton, could not go because they were "too dangerous." When her account was challenged by one of her traveling companions, the comedian Sinbad, she upped the ante and injected even more drama into the story. In a speech earlier this week, she talked about "landing under sniper fire" and running for safety with "our heads down."
It turns out that the story is completely false.
Had Hillary Clinton's plane come "under sniper fire" in March 1996, we would certainly have heard about it long before now. Numerous reporters, including The Washington Post's John Pomfret, covered her trip. A review of nearly 100 news accounts of her visit shows that not a single newspaper or television station reported any security threat to the first lady. "As a former AP wire-service hack, I can safely say that it would have been in my lead had anything like that happened," Pomfret said.
According to Pomfret, the Tuzla airport was "one of the safest places in Bosnia" in March 1996 and "firmly under the control" of the 1st Armored Division.
There is even video of Clinton landing at the airport and conducting a photo-op with a young Bosnian girl. If Al Gore had told this tale, the press would have devoured it. If Barack Obama had made a similar claim about his foreign policy chops and was later proven wrong, it would be a huge deal. But this is somehow not breaking through.
The point here is not that the press is easier on Clinton than Obama, but rather that this story does not fit into the media's narrative of Senator Clinton--experienced, competent, tested. And therefore's it is not really a big story.
Update: Chris was here first.