I've long been convinced that the effect of blogging in the Actual World will be movement towards the political center. My thinking is simplistic. Political stuff that is insular -- magazines, talk shows, talk radio -- leads to extremism. Why not? You're only talking to the converted, and the echo chamber gets amplified. Blogging, by contrast, is inherently more open, prone to dialogues. Blogging doesn't WORK unless there's something to argue with, feuds to pick, opponents to needle. Thus, you go with arguments that try to convince, and attempt to make your arguments media-savvy.
The Ann Coulter/Edward's Bloggers bit forms a neat example. Both sides, acting independently, got the more extreme bits of the Edwards Campaign and the Republican Opposition neatly excised. Coulter may finally be finished on the national scene, as Conservative Bloggers call for her ouster. If you're fighting a war against Democrats, after all, you don't want such an obvious vulnerable point on your side.