The New York Times today PDF) by the Pew Internet & American Life Project about the influence of (the big, political) blogs on American political discourse during the last two months of the 2004 presidential election.

The summary of the findings says:

• Blogger power … is circumstantial: dependent on the sorts of information available, and contingent on the behavior of other public voices
• Political bloggers were buzz followers as much as buzz makers.
• Bloggers may have been positioned in the fall of 2004 as a guide for the mainstream media to the rest of the internet.
• The key contribution by the bloggers in the “Rathergate” scandal consisted of providing forums accessible to all internet users in which facsimiles of the memos could be examined and discussed.

There’s also this wonderful description the political blog genre, which neatly summarises its limitations:

Political blog entries often consist of a clever headline, an excerpt from and link to a news report with a fresh detail, and a captioning phrase of approbation or contempt.

Go read the lot.