The Press Effect suggests the media frames issues and candidates in a way that their future stories on the subjects will tend to fit neatly inside the pre-conceived box. Since the media is a follow-the-leader game, once a frame takes hold it doesn't let go very easily. Jamieson and Waldman use this theory mainly to explore the 2000 Election between Gore and Bush.
Gore's many misstatements through his political career led the press to frame him as dishonest. Bush's flubs through his short political career convinced the press to put him in the frame of unintelligent. The result were campaign stories that asked voters to choose between the smart, but untrustworthy Gore and the dumb but affable Bush. The examples of media coverage in the book support this theory pretty well.
Next the authors cite the examples of Gore's untruths and basically defend each one as a misunderstanding, leaving Gore as a more honest individual than painted by the media. As a reader, I anticipated the authors next explaining that Bush was actually a smarter man than he was given credit for, after all he has an MBA from Harvard. Instead the authors quote a New Yorker article where a reporter cites George W. Bush's average grades at Yale. This is was a surprise, because the story was unverified by Yale and it doesn't take into account that grades have much more to do with ambition and drive than intelligence. There was no attempt to give Bush the same credit that the authors spent giving Gore. An opportunity to support their main thesis was left on the floor, which gives one the feeling that the real purpose of the book is to defend Gore not shame the media. This same pattern is repeated when the authors discuss the Florida recount.
It's unfortunate that Jamieson and Waldman abandon the scholarly for the advocacy role because there is a lot of other research in the book that seems dead on. They bemoan that fact that reporters do a terrible job of verifying the evidence and drawing conclusions. Instead, the authors argue that the media play into the "he said, she said" game of political strategy. The story becomes about how the candidates disagree with each other on their positions more than the actual substance of those positions. They also state that the media loves to play psychologist when they should instead be playing fact-finder.
I found the basic theories in the book supported by good evidence. But the advocacy of Gore and the silence on Bush in the analysis sections detracted from the book's purported goal of exposing the media's laziness. I'm sure that the authors would say that they had no intention of propping up Gore, but parts of the book seem to strengthen the media frame on Bush which weakens the overall argument of the book. This is surprising since Bush could have been defended as easily as Gore.
Anyway, I think the authors do a fine job casting a spotlight on the media's "follow the leader" approach and that's enough recommend it despite my other misgivings.