Shirky's piece, linked below, refers to Steven Johnson's stevenberlinjohnson.com: My Theory About Dean's Demise: He Got Fewer Votes Than The Other Guys:
I've been quoted in a couple of places saying that the Dean campaign was more like a system running for President than a candidate, and I think the last month has illustrated the downside of that phenomenon, which is that all that attention paid to the blogs and the Meetups distracted everyone - the media, the voters - from the candidate himself.
