In case you need further evidence for Democrats dependence upon the left-wing blogosphere, consider this quote:
DCCC Executive Director John Lapp issued a statement defending the committee. Saying the DCCC would like to fund every House race, he said: "Resources are not infinite. That is why MyDD, the Daily Kos, and the larger blogosphere are so important. You are critical in the effort to expand the playing field well above and beyond the 30 or 40 districts typically in play."
When the Democratic Congressional Campaign Committee embraces and applauds what can only be described as the far Left, where conspiracy theories abound and invective and profanity often replace argument, the party is simply further marginalizing itself.
This of course does not mean that the Republicans have no problems of their own, as the article (quoting Newt Gingrich) indicates. But Democratic extremism makes it easier for Republicans to avoid facing their own weaknesses.