BLOG POWER! Continuing his welcomed crusade to infuse blogospheric filibustering with actual data, Scott Winship has some additional information on the size and potential power of the Netroots. A few caveats, though: cross-comparisons of group numbers only work so long as the average member of each organization exerts an equal amount of influence. The reason interest groups matter, after all, is because they're pockets of frenetic activity in an otherwise apathetic landscape. So when comparing the size of the Netroots to, say, the size of the Sierra Club, it's not enough to merely look at how many claim membership, but what membership means, how much direct action it entails, and how sustainable that is.

Indeed, my sense is that if you take into account the wider number of actions and tactics deployed by active Netroots participants, you'd return with an impression of strength that is disproportionate to its numbers. Some of that is attributable to the blogosphere's superior ability to conduct direct action. Some of it relies on self selection -- I'm on a number of activist e-mail lists I don't check or care for, but whenever I surf to a blog, I've demonstrated a distinct interest in the content and mission of that site. My guess is that leads to a far higher participation rate for blogs than e-mail lists. Further, the blogs' ability to actively involve readers in the planning and perpetuation of campaigns may also aid participation. Or, maybe everything goes the other way, and most read the blogs for news, and participate rather seldomly. I don't know. But that, more so than even the raw count of daily readers, actually decides how powerful a force -- and how loud a noise -- the blogs will make in coming elections.

--Ezra Klein