Alterman is clearly a believer that the "netroots" movement has had a positive effect on the public discourse. His example - Atrios - is a blogger.
Chait's narrative of how the netroots saw the Florida recount strikes me as a great deal more accurate than anything anyone would have read anywhere in the MSM at the time--again, given what we now know to be true. The Iraq case is even stronger. One could make a sound empirical argument--based on virtually every major event in the Bush presidency--that the MSM narrative was a convenient invention of self-interested parties while the analysis that permeated the netroots has been largely borne out (so far) by history. Had, say, Atrios been in charge of things, rather than the figure in the White House--whom Tim Russert mused at the time was sent by God for just this purpose--hundreds of thousands of people would still be alive, Americans would not be more hated than at any time in our history, we would not be creating terrorists faster than bathroom germs, and most TNR editors would have a great deal less for which to apologize to their readers. . . . Thanks in large measure to the netroots "movement" Chait describes, Americans can see a great deal more clearly today than yesterday, and, as far as I can tell, we're a hell of a better country for it.