I believe in you that it isn't a requirement. What I'm saying is that he claimed to be black and it was ok... it should be in that link from "veja" I sent you, but unfortunately only the printed version had his name (saw it like one year ago).
It was her personal choice, she married a black man, she felt black, she teached about black culture, etc... it may have lead her to a position of power, but it doesn't seem like it was the primary reason. But even so, that is one of the reasons I'm completely against reparations, quotas and things that are based on discrimination because not only it perpretates the discrimination as it is exploited by bad individuals.
I checked the Veja article. Bill de Blasio's chidren aren't considered black here. We'd call them biracial. I'm not seeing anything about a guy accepted just for a single black ancestor but you said that might have just appeared in the print version of the article. Any chance you can find it online? I still think it's irrelevant because they'd let him whether he had a black ancestor or not.
As for reparations and such, I fully agree with. And so does the NAACP to an extent. They don't want monetary compensation but for corporations that were complicit and profited from slavery to develop programs such as job training, inner city health clinics, schools, etc.... Things a socially conscious corporation often does anyway.
Massimus - "Trump already has democrat support."