I noticed how not black not Obama is (compared to someone who is actually black) long ago and chalked it down to the US heritage of slavery and the one drop rule.

One-drop rule - Wikipedia, the free encyclopedia

The one-drop rule is a historical colloquial term in the United States that holds that a person with any trace of African ancestry is considered black unless having an alternative non-white ancestry which he or she can claim, such as Native American, Asian, Arab, or Australian aboriginal.^[1] It developed most strongly out of the binary culture of long years of institutionalized slavery.

If you have race-based slavery or other legal discriminations (South Africa and Nazi Germany springs to mind) then you need clear definitions. And those definitions are going to be arbitrary. Slavery as it has existed elsewhere has generally not been strictly race-based in the sense that all of a certain cathegory are slaves, and no others.

Fitting image for this thread:

First time I looked at it it took me a moment to realise that they had actually altered Obamas picture too...

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