These house meetings form the core of the campaign's organizing model. The concept derives from organizing theory as taught by Saul Alinsky and as adopted by community organizers across the country. Never before has a major party presidential campaign used them to expand their support in a general election. (emphasis mine)

Nice of Ambinder to acknowledge that, even if he doesn't actually mention the Dean campaign, for which house parties and meetings were a major organizing tool. In many ways the Obama campaign is the Dean campaign perfected and expanded, probably because while Dean had good instincts and trusted the grassroots, he and his top people did not (to my knowledge) have much of a community-organizing background; they just lucked into it. It's great to see so many of the things we were making up as we went along four years ago built upon so masterfully!