Is it 'cause he's Black?..Well, yes, actually.

Yes it's politically incorrect but race matters
The 2008 US election has all the makings of a Greek tragedy, in which noble heroes and heroines are forced to follow a course to catastrophe, divinely preordained as punishment for sins and blunders committed by their forefathers in the dim and distant past. In acting out their ineluctable doom, the eloquent protagonists do not just destroy themselves but also their cities, their nations and even their entire civilisations. If this description sounds too grandiose, consider yesterday's results from the Pennsylvania primary. The outcome seemed to be precisely calibrated by the gods to maximise the agony of the Democrats. It gave Hillary Clinton just the support she needed to stay firmly in contention, but not quite enough to turn the tide in her favour. Worse still, this result underlined the fear that senior Democrats have long been aware of, but have never dared to express in public: America may not yet be ready to elect a black President.
The most shocking revelation from polls in the US is that millions of Clinton supporters would either not bother voting or would actually vote for McCain rather than vote for Obama.