The reaction to Sullivan's thesis ranged from apathy (Drum) to quasi-agreement (Digby) to derision (Atrios.) For my own part I'd say I think the efforts to broaden the party are always a good thing as long as it doesn't entail the party sacrificing it's core values. Any attempt to accomodate evangelicals at the expense of the party's positions on abortion or homosexual rights, for example, will simply piss-off a good portion of the base and prove once again party leadership doesn't get it. We are tired of mealy-mouthed weenies representing us. We are tired of being taken for granted.
The Democratic party leadership often seems to forget that it doesn't have to remake the wheel when it comes to emphasizing religous values. The party has a long tradition of working for real social change in conjunction with religous leaders on labor issues, civil rights, social justice, etc. If the party wants to appeal to religous Americans they might emphasize more of this. Peace is the ultimate Christian value.