I think Ezra at Pandagon makes a very sharp observation about, more or less, the dangers of confirmation bias:
I can't tell you how optimistic I was going into this election, though, looking back, there doesn't seem to have been a reason for quite such a sunny view. But I, like most of us, fell for the echo chamber. Daily Kos, MyDD, Steve Soto, Pandagon, and all the other blogs are run by good people with positive intentions, but if they're you're primary source for information, you're outlook is perverted by an overwhelming amount of good news and a general disdain for the factual accuracy of bad news. It perverts your perspective and, because the sample group is so totally different than most of America, it begins to twist your political predictions and assumptions of what works (for more on this, see my article Power Trippi). So the first lesson, insofar as I'm drawing them, is remain a member of the reality-based community, and too many blogs and partisan sources can compromise that.
I think liberal activists really ought to sit down and read a couple Left Behind books, go to a few services at a suburban evangelical megachurch, and really study Bush's message and the way it animated these people. And be on guard for your love of affirming news, and skepticism of bad news. That's not just an essential habit of intellectual integrity, it's also practical.