See NYT article here.
[T]he reason The New Yorker’s cover seems to have fallen short is precisely that it brought out into open, respectable space an idea of the Obamas that is still, happily, considered contemptible. The portrait of them as secret Muslims, in cahoots with terrorists and harboring virulent anti-American sentiments, exists for the most part either on the lunatic fringe or in what some might call the lunatic establishment: radically partisan entities like Fox News. If, on the other hand, this newspaper began politely referring to Senator Obama’s radical Islamic sympathies, then a full-blown exaggeration of that insinuation into ridiculous satire would be just what the doctor ordered. . . .
In satire, absurdity achieves its rationality through moral perspective — or it remains simply incoherent or malign absurdity. The New Yorker represented the right-wing caricature of the Obamas while making the fatal error of not also caricaturing the right wing. . . .
But if that very same New Yorker cover had been drawn in a balloon over the head of a deranged citizen — or a ruthless political operative — it would have appeared as plausible only in the mind of that person. The image would have come across as absurd and unjust — a version of reality exaggerated to the point of madness.
By presenting a mad or contemptible partisan sentiment as a mainstream one, by accurately reproducing it and by neglecting to position the target of a slur — the Obamas — in relation to the producers of the slur, The New Yorker seems to have unwittingly reiterated the misconception it meant to lampoon. . . .