BLOGS AND GROUPS. Noam Scheiber, in this whale of a post, teases out some of the implications of the interactions between netroots types and traditional liberal interest groups that Garance wrote about yesterday. I think the macro-level impact of the rise of netroots influence should actually be pretty easy to summarize -- ceteris paribus it will make the party less liberal on the issues that are really, really important to key interest groups and more liberal on the other issues.
And I think that's generally what you've been seeing: somewhat more flexibility on, say, abortion but for the first time serious efforts to counter the influence of the business lobby over formerly obscure issues like bankruptcy reform and telecommunications regulations. And, of course, questions of war and peace, where Democrats have traditionally felt totally free to spurn the sentiments of liberal voters, counting on loyalty to the key liberal interest groups (none of whom care about any non-trade aspects of foreign policy) to pull them through.
What you think of this will, I think, more or less come down to what you think about some national security issues and the politics of national security. Insofar as the rise of online civil society makes the country less likely to continue on a course of militarism run amok, that seems good to me even if there's an electoral price to be paid. And, personally, I doubt there will be a price to be paid because I doubt efforts to "outflank" the GOP as the party of grandiose nationalism can be made to work. But I also imagine the median New Republic writer doesn't see it that way.
That said, I generally doubt that systemic social change will radically alter election outcomes since I tend to believe that the parties will more or less alternate in power -- the important issue is the terms of debate between the two parties, and I think that insofar as the netroots become more influential (which I think is a fairly open question) the aggregate impact will be positive. The great benefit of the blogosphere is that it isn't really an "interest group"; it's more like an old-style membership organization (or a series of such organizations) whose existence used to do something to check what's now become the out-of-control influence of business groups over the policy process.