[btilly]

It seems more likely that this was an Obama campaign advantage, rather than a Democratic party advantage.

Judging from the emails I'm getting, Obama would like to turn it from a campaign advantage to a governing advantage (here are all of my current policy issues, please put pressure on Congress to do X, Y and Z), and if he succeeds in that he will undoubtably try to turn it into a party advantage in the future.

So yes, the organization is fluid and can evaporate. The database of possibly politically active people is much less fluid, and may prove to be a more durable advantage.