Nott read an article entitled "VITAL STATISTICS OF NEGROES AND MULATTOES" which appeared in 1842 in the Boston Medical and Surgical Journal. The author, writing under the pseudonym "Philanthropist," showed that according to the mortality statistics in the 1840 census, there were twice as many deaths for the free group than for the enslaved. Inasmuch as there were a great many free mulattoes among the "Free Colored," Nott developed a mulatto frailty theory to explain the reason this group appeared to be dying at a much faster rate than the "Slaves." He also developed a mulatto sterility theory in order to explain his "observation" that mulattoes were less prolific than either whites or blacks. These theories were first published in 1843 in an article for the American Journal of the Medical Sciences entitled, "The Mulatto a Hybrid--probable extermination of the two races if the Whites and Blacks are allowed to intermarry." A reprint appeared shortly after in the Boston Medical and Surgical Journal. Dr. Nott may have been knowledgeable in the field of medicine, but he was certainly no ethnologist. Ridiculous as it seems today, Nott conceived of the mulatto as a hybrid different than either white or black. He reasoned that just as the horse and donkey are different species and produce a sterile mule as hybrid offspring, so too white and black are different species and produce a sterile mulatto.- Multiracial Activist
Below, from Living in the End Times, is a masterpiece of alibi construction. Zizek makes it easy for his fans to lap up this delicious vintage racist fantasy of the most lurid and prurient kind by supplying flimsy but adequate means with which they can pretend to be enjoying the imagery only to denounce the loathesome Sarah Palin who is somehow held responsible for it:
Earlier generations of women politicians (Golda Meir, Indira Gandhi, Margaret Thatcher, up to a point even Hillary Clinton) were what is usually referred to as “phallic” women: they acted as “iron ladies” who imitated and tried to outdo male authority, to be “more men than men themselves.” In a recent comment in Le Point, Jacques-Alain Miller pointed out how Sarah Palin, on the contrary, proudly displays her femininity and motherhood. She has a “castrating” effect on her male opponents not by way of being more manly than them [sic], but by using the ultimate feminine weapon, the sarcastic put-down of a puffed-up male authority – she knows that male “phallic” authority is a posture, a semblance to be exploited and mocked. Recall how she mocked Obama as a “community organizer,” exploiting the fact that there was something sterile in Obama’s physical appearance, with his diluted black skin, slender features, and big ears.
Palin is described exploiting that fact and this therefore, we can assure ourselves, is why we have this fact of the President's look of sterility here before us at all, requiring our attention. Zizek delivers the "sterility" of "Obama's physical appearance" due to the "dilution" of some supposed earlier blackness and "big ears" as fact to his fans for their delight equipped with the excuse that they are only savouring it in their righteous effort to deplore the always deplorable Sarah Palin's unscrupulous exploitation of it and expose her emasculating machinations.
Zizek frequently images Obama as the victim of his "big black guy" taming tale (he has stolen his magic penis, and more recently coerced him to beg to be called the n-word, but also fantasised that he was white underneath all along, never really the undiluted threat with the prehensible membre virile) and here appoints Palin the surrogate assailant of his own fantasies, whom he can then chastise and rebuke for carrying out his wishes. Her cruel castrating use of the fact of Obama's mule/mulatto sterility is slipped clumsily (but deftly enough to satisfy the fanatical devotees of the sage) into an implication that Palin, not Zizek, is really the author of the fact illustrated by the imagery. In Zizek's account now, it is she, Palin, not he, who is engaged in the production a spectacle of castration and conquest of Obama. (Palin - the devil - made him do it!) It is she, Palin, not he, Zizek, who is disturbed to frenzy and mental breakdown by the fact that Obama is the child of a white woman and a black African man, evidence of that relationship, and that it is she, the seductress witch Palin, and not he, Zizek, who envisions this couple as mare and donkey and has emasculated Obama symbolically and made him into the sterile mule of Zizek's racist phantasmagoria.
With the very hamhandedness of his non-sequitur (asking his audience to accept that Palin's "community organizer" plainly signifies Obama's "diluted black skin" and "big ears" as signs of sterility, but simultaneously to deny with the shrill outrage of repression that "mule" and "mulatto" and their historical association in white supremacist mythology are evoked by Zizek's terms "big ears", "diluted black skin" and "sterile" applied to the appearance of the President whose mother was white and father black) Zizek winks at his droolingly adoring followers as he tosses them this little dripping nibble, sealing an agreement to insist that this vision of Obama's "sterile" physical appearance - his "diluted" blackness, his big ears, his equine slenderness- is not the putrid ooze of Zizek's own diseased mind but has imposed itself on Zizek's text from outside - a Palin figure has plucked it from "reality" and left it on his doorstep - and he has only stepped in it. He poses as, and his audience pretends to believe him, inconvenienced by this imposition, asking the audience to accept that the fact of the sterile appearance of an emasculated Obama is something for Zizek to scrape off his shoes, matter to be righteously rejected, in the vein of his brave and righteous rejection of the identification of the soldiers defending against the seige of Crete à Pierrot as "half-apes whose grandparents jumped in trees like apes in Africa". He asks to be applauded for chastising the inexcuseable Palin for taking advantage of the President's misfortune.
There won't be an open letter to Verso about Zizek's mule even though many more unsuspecting eyes will be violated by it than by his competitor Johnson's baboons, attacked to ensure above all that Zizek can continue to derive legitimacy and leftist cred from his appearance in a publication that his devotees among the signatories all confide "is progressive" - it is this reputation that is safeguarded and burnished by the caper - and wouldn't publish racism, reaction or revisionism. If there are one or two Zizek devotees who find the use of this imagery ever so slightly distasteful, their main concern will not be the alarming, obviously successful beginnings of a revival of another deeply offensive and until now really forgotten trope (it was evoked to shocking effect in the mouth of Harold Pinter's vicious Antigua planter/English Baronet in Patricia Rozema's film of Mansfield Park), and the whole until recently utterly unfashionable, utterly universally deplored  discourse of "miscegenation"  and "diluted" races, in which it is embedded. Their concern will be only how to defend the passage as leftist, as sloppy, as trivial, as wholesome provocation, as ironic, as brave rebuttal to all the hordes of leftists, liberals and progressives who believe the children of one white and one black parent cannot reproduce, as an important "critique" of Palin's persona (or rather, of her vagina) and of liberalism. Their self-imposed duty will only be to not interfere with the hardcore ZizneyCorp's efforts to protect from criticism this precious ground occupied - to establish this fact on the ground - contributing to the full scale reconquest of the ideological territory of the mainstream by neoHegelian race theory and the restoration of its vocabulary, its abstractions, to intelligibility and currency. The breakdown of rationality and logic, the promotion of sophistry in place of argument, the discrediting of historiography, evidence, documentation and proof, and the legitimization of self-serving, convenient, cartoonish revisionist fables, (most often relating stories of uppity black men put back in their subordinate place through a display of the omnipotence of European Mind (P.114)) is necessary to imperial ruling class revanchism and requires painstaking long- term labours.
White supremacy is a praxis.
Some cocaculture, for example David Lynch's films, deploy allusions to this discourse and its terms of course, but as "dream imagery" and "metaphor" muffled by many layers of disavowal, irony, reflexivity etc..
 a concept also recently granted the first hesitant step toward reassertion in theNew Left Review where it is evoked as the horrifying consequence courted by cultural "creolisation"