I think some combination of Digby's and Christy's posts really gets the issue quite well. Tribalism in American politics is incredibly important. While I think that most "swing voters" in the presdent day are that way because of a combination of ignorance, apathy, and a desire to imagine themselves to be "independent" (think of them as "Slate readers"), the greater pool of potential swing voters are indeed motivated to a great degree by tribal self-identification.
But that kind of tribalism can't, for the most part, be pandered to by most national politicians. It's long term and it's largely local. Neither George Bush lying about what cheese he puts on his cheese steak nor national Democrats expressing their love for country music (real or not) are going to impact tribal identification long term. Sure nods to tribal identity put pull a few votes back and forth, but long term the goal is get the whole tribe back in your camp.
That's why revitalizing the local party and related institutions at a local tangible level is so important. It also makes it easier to, as Christy points out, actually provide real results to people who need them.
