Phenomena vs. Noumena
i.e. It's not about race (or gender), but ideology.
Leftists are much more about image, appearances, than substance, i.e. Kant's phenomena vs. noumena, because their substance is unappetizing to a majority of Americans with any common sense, and to make the sale the leftist--more often than not-- tries to look and sound conservative when the inner reality--the noumena-- is that he or she is not (engaging in illusion and/or deception right off the bat, with no scruples about it).
Kant, it should be added here, said that the noumena was unknowable, and that is true, to a certain extent, but glimpses of it can be discerned if only by contrast to the phenomena, e.g. if a phenomenon publicly communicates a certain virtue (e.g. honesty) but the carrier of that phenomenon is known to behave in a characteristic pattern of deceit, you know that the phenomena does not square with the noumena.
[Of course, none of this is to premise that the Idealism of Kant's German Enlightenment philosophy is necessarily True, only that--like Freudism--there are some good points here and there that ring so.]
Note that Clinton, in 1992, promised a cabinet that "looked like America."
How things "look" vs. how they are.
Hillary's choice of wearing Margaret Thatcher blue for Super Tuesday invited credible accusations that she was trying to invoke the conservative Iron Lady--i.e. by the color she was wearing, how she looked.
Of course, since 1963, Democratic primaries have been beauty pageants that would decide who invoked JFK the most, but by superficial qualities alone, for by comparison to the other Democrats-Who-Would-Be-Kings since his assassination (Bill Clinton included, despite being the most succesful doppelganger), JFK was, essentially, Reaganesque (by comparison, mind you) while the others were not.
They love the image, however.
Barack--and his wife--are a class act and he even sounds and carries himself like a conservative (e.g. he doesn't make race an issue). I personally like and respect him (and find it fitting that he may be the Van Helsing who drives the stake into the heart of the vampiric Billary), but he would be easier for McCain to beat than the Billary machine would be because of the latter's triangulations to the right and McCain's record of leftward lurches vis-a-vis policies.
The phenomenon of Barack is taking him a long way, but the noumena of his liberalism will sink him in the general election (if he does go on to win the nomination).
Billary met McCain in the middle on just about everything, and a McCain win would be done primarily by likeability vs. Hillary's negatives (though McCain has his own fair share of negatives, perhaps offsetting Hillary's own among their respective party bases).
Barack, on the other hand, has the most liberal voting record in the senate. Despite the "L" word being notably--and strategically, to be sure-- absent when talking about Barack ("Progressive" is preferred), he's still a liberal, and America-At-Large--still, despite signs of decay brought on by liberalism-- ain't.
McCain can pull off comparing himself to Reagan when up against Barack, but when up against Billary he's indeed more Bob Dole (and that was Romney's point, i.e. Clinton beat Dole, because Dole, like McCain, was much more a Republican than a conservative.)
Regarding Romney's own phenomena vs. noumena, I think Stewart on "The Daily Show" (although I don't recall which comedian from what show ran it ) showed a montage of Romney at a barbecue. The guy picked his teeth with his finger and put some meat back on the grill after it fell on the ground.