It always gives me pause to disagree with the brilliant John Judis, so I read his gloom and doom articles about Barack Obama's electability after every primary with interest. Still, I don't buy it. If it's true that Obama has trouble winning over Hillary Clinton's core supporters because of their deep-seated aversion to Obama, then how is he leading in the national polls against McCain? I think Clinton's voters are loyally backing her because they like Hillary Clinton a lot and given her status as a quasi-incumbent, party leader, and her husband's wife it's very hard to knock her off that pedestal.
To make a long story short, John's way of looking at the race seems to simply exclude the possibility that both Democrats are running strong campaigns. But I don't see any reason to view either candidate's trouble as reflecting "weakness" as opposed to his or her opponent's strength.