The interesting thing in this case however, is that, where he a citizen of Central of Southern America there would be more than two possible racial categories to which he could conceivably belong. The US is unique AFAIK, possibly globally (even Apartheid South Africa had "coloureds"), in that it only recognizes black and white as binary choices. This derives directly from slavery and segregation and the racial worldviews which are adopted legally from them (although slaeholder logistics could become more detailed).

The interesting question then is whether he would be considered "black" in Kenya, or indeed whether there such classification issues might even arise. Apparently it does arise and there's some sort of "light is right" fad in Kenya:

In Kenya, being mixed race is an automatic stamp of beauty. So called point fives are considered aesthetically superior regardless of the symmetry of their features. We tend to describe beauty or lack thereof using skin colour as a focal point.

Even more interestingly, as I find out perusing the oracle at google to answer my own question, there seems to be a surprising situation regarding the attitudes of mixed-race Africans, self-described as "coloureds", towards their black neighbours:

What - and this is the distressing part - what most unites the coloureds is their hatred and fear of, and contempt for, the Africans. In Zambia, carefully avoiding more obvious words of abuse, and thus avoiding trouble, coloureds have their own term for their black neighbours. They call them 'pops'. Why, no-one seems to know, but you'd be amazed how insulting that word can sound. 'Man, these pops, they're useless!'

(In the same article I learn that Bob Marley was mixed race too. I'm stunned I didn't know this already. Through this article I learn about the fascinating Namibian Basters).

Anyway, I note in passing that the first mulatto president anywhere in the world is probably Alexandre Pétion.

The road of excess leads to the palace of wisdom - William Blake