Dana Blankenhorn provides a nice write-up of what's underlying the potency of the Dean campaign (posted at Greater Democracy):

The Dean Campaign creates, embraces, enhances, validates, and rewards intimacy. The Dean Campaign gives people something they have lost, not just in politics but in life.

[...] What is the key message of the Dean Campaign? It was the close to his announcement speech. "You have the power." You really do. Money doesn’t have it, Washington doesn’t have it, the pundits don’t have it, David Yepson doesn’t have it, Dana Blankenhorn certainly doesn’t have it. You have it. You. Out there, whoever you are and whatever your story.

[...] That’s the secret of the Dean Campaign. Yeah, it’s as corny as a Frank Capra movie. But the blogs, the campaign, the Meetups, they all deliver that same power, that same intimacy. They return Americans back to a sense of themselves as powerful, important, worthwhile.

And we need that. We need that now. We need that bad.