Mark Schmitt gets this exactly right:
As an observer of politics, and commenter on it, I almost entirely share Krugman’s and Edwards’ diagnoses. I appreciate the conflictual nature of politics. I don’t think there’s some cross-partisan truth; I understand that the Republican conservatives are intractable. I know those advantaged by the current structure of power are determined to preserve it, and the well-funded campaign to destroy any possibility of progressive governance will be as intantaneous and intense as anything in 1993. I’ve tried to spell this out as clearly and aggressively as possible, especially to counter the tendency among elites to imagine that the good old days when Republicans and Democrats worked together selflessly and put ideology aside to solve the nation’s problems are coming back. (Or that they were so great to start with.)
But let’s take a slightly different angle on the charge that Obama is “naïve” about power and partisanship. Suppose you were as non-naïve about it as I am — but your job wasn’t writing about politics, it was running for president? What should you do? In that case, your responsibility is not merely to describe the situation exactly, but to find a way to subvert it. In other words, perhaps we are being too literal in believing that “hope” and bipartisanship are things that Obama naively believes are present and possible, when in fact they are a tactic, a method of subverting and breaking the unified conservative power structure. Claiming the mantle of bipartisanship and national unity, and defining the problem to be solved (e.g. universal health care) puts one in a position of strength, and Republicans would defect from that position at their own risk. The public, and younger voters in particular, seem to want an end to partisanship and conflictual politics, and an administration that came in with that premise (an option not available to Senator Clinton), would have a tremendous advantage, at least for a moment.
To accept the obvious truths that politics is about conflict, that many political disputes are incommensurable, and that partisanship is therefore not inherently a bad thing does not mean that repeatedly emphasizing conflicts is an effective rhetorical strategy. To take Obama’s rhetoric on this score at face value is silly. It’s overwhelmingly likely that he understands perfectly well the nature of the GOP, but also understands that “the current GOP is horrible and we should therefore kill them and then salt the earth so it can never grow again” isn’t an effective means of appealing to swing voters.
..and as for political efficacy, the fact that Obama substantially outperforms Clinton against anybody seems definitive.