One thing I have noticed about this blog is that it has quite a few partisans and not so many independents. And I think that there is a big difference in the way partisans and independents think.
Partisans for example place a much higher value on winning. Independents tend to place more value on whether or not things will actually change. For example a partisan might support Zell Miller or Gray Davis. Independents on the other hand would rather see them lose even if it hurts that party.
Because of this also partisans are more worried about electability. Clark even though he is a centrist is primarily seen as electable and if he didn't have that percieved electability edge he would not even have gotten as far as he has.
On the other hand I don't think Clark would be as good at attracting independents as Dean. Dean attracts them by focusing on things like a balanced budget and showing that he is perfectly willing to criticize his own party. Clark on the other hand I'd say turns off independents because of his praise of both parties and because there is a question of where he stands on the issues. Independents aren't independent because they like both parties. Clark would be better at attracting partisan Republicans. Independents also place a higher value on having strong positions because that person will be more likely to stand up to their party whereas someone with fluid positions is more likely to be controlled by the partisans.