Black supremacy

...Black supremacy is as dangerous as white supremacy, and God is not interested merely in the freedom of black men and brown men and yellow men... Black supremacy is a collection of horrendously vacuous racialist and fascist ideologies that developed in response to white supremacy. Many of the largest black supremacist groups are black Muslim separatist movements like the Nation of Islam (though black Jewish separatist groups like the Nation of Yahweh also exist). Essentially, the more anti-Semitic, anti-white, homophobic segments of the black nationalist movement such as the New Black Panther Party act as a black version of Neo-Nazism.

Pseudoscience
The ideology of black supremacy, of course, is the mirror image of white supremacy. While different groups put their own spin on things, black supremacy often involves the racialist pseudoscience called "melanin theory" and the pseudohistory called "Afrocentrism". The basic idea behind melanin theory is that black is the "natural" skin color because humans originated in Africa, so lighter skin tones are aberrations. Various melanin theorists build on top of this, positing all sorts of biologically unsupportable claims about melanin increasing muscle tone, brain activity, physical ability, etc. Some theories get into really batshit territory, claiming that melanin can grant paranormal powers like ESP. These pseudo-scientific beliefs may express themselves in sexual language and practice. For example, the Urban Dictionary says:

Afrocentrism
...Has nothing at all to do with hairstyles popular amongst black people.

Afrocentrism and melanin theory often cross-pollinate, but Afrocentrism as a separate concept has a historical rather than biological focus. It's important to separate legitimate historical revisionism from the kind Afrocentrists engage in. The early histories and ethnographies of African cultures were written largely by European historians and anthropologists from an imperialist perspective. Thus, these works are often skewed by racism and filled with factual inaccuracies, and are outdated due to new findings in archaeological and historical scholarship. There have been many revisionist works throughout the 20th and 21st centuries that attempt to look at this history from an African perspective, but remain factual. This is simply an attempt to "correct the record". Afrocentrism, on the other hand, engages in distortion and fabrications of its own. One of the central claims of Afrocentrists is that Egypt, being in Africa, was ruled by a black super race. They use this to claim that Greco-Roman civilization, and by extension, Western civilization, is actually based on black culture. Working from this point, they rewrite many historical figures like Socrates as having been black and shoehorn various events into the ideology.

When called on their bullshit, they tend to justify their factual inaccuracies by claiming that critics are using a Eurocentric methodology that is unable to ascertain a true understanding of history and that only those using the Afrocentric methodology can do so. And just for the record, Ramesses II was a ginger.

Similar crank claims point toward India (implying that the existence of the "Negrito" people means that Indian culture came from black Africans, and the Dravidians are so dark that they must be Africans); China (depictions of people in dark materials imply they were black; for example, the Terracotta Army); Japan (Jomons would have been black, and so were the Ainu, as they used black bronze in their sculptures, and were painted in light-brown, which is clearly whitewashing from the Japanese bigots, never mind that the Ainu are still around and definitely not black); and the Mongols ("black khans"). In America, they rewrite Central America, Aztecs, Mayas, and particularly the Olmecs, since they had wide noses in their statues (like many Native people from the region today, but let's forget about that). So yeah, it might have been easier for us to list all the ethnicities and cultures they don't try to shoehorn into having somehow secretly been black.

Republic of New Afrika
The Republic of New Afrika is a black nationalist/separatist movement that advocates for the creation of a blacks-only homeland/country separate from the white-majority/diverse United States. The movement was founded in 1968. The three goals of the New Afrika movement are:
 * Creation of a black-majority country centered in the Black Belt region.
 * A $400 billion Payment by the federal government as reparations from America due to enslaving blacks, Jim Crow laws, and racism.
 * A referendum of all blacks to determine their desires for citizenship and self-determination.

Various black nationalist groups have advocated for the creation of the Republic of New Afrika over the years and the movement is still on going.

Strange bedfellows
Oddly, some Black supremacist groups have formed friendly relations with White supremacist groups. Part of it may be that both ideologies tend to promote anti-Semitism, misogyny, and homophobia. Another reason is a shared belief in ethnocracy and separatism: both ideologies agree that the "races" are fundamentally incompatible with one another, and thus have the common end goal of a series of separate ethno-states for each "race". So if White Nationalists want to move all the White people to, say, Montana, and Black Nationalists want to move all the Black people to not-Montana, they both have the same goal. The devil is always in the details of course; it's unclear who would get the mixed-race people, or if they would be forced into a third ethno-state. Louis Farrakhan of the Nation of Islam invited the neo-Nazi Tom Metzger to NOI meetings. Metzger remarked:

Support for racial separatism also tends to unite both ideologies.

The Black supremacist sect that probably most promotes anti-Semitism ironically identifies itself as "Black Hebrew Israelites." This ideology has its roots in post-bellum Pentecostalism, which transmuted into "Black Judaism." According to Black Judaism and Black Hebrew Israelism, the newly freed slaves of America's South were the true Hebrews and descendants of the tribes of Israel (an assertion that mirrors the Christian Identity theology held by some white supremacists, which claims Aryans as the true Hebrew race). F.S. Cherry, a late 19th century proponent of Black Judaism's more hateful elements, also preached about a race war with apocalyptic overtones that would supposedly occur in the year 2000 and refashion society into one where blacks were the superior race. The belief that blacks are the "true" Hebrews also leads many in the Black Hebrew Israelite movement to espouse anti-Semitic pseudohistory such as the Khazar myth and Holocaust denial.