If Frank Marshall Davis - friend of Stanley Dunham - was the baby daddy, why even assume that such a union was consensual? The Dunham family was disfuntion junction, so really no stretch to consider if a misogynist pops conjured up the Kenyan exchange student to cover for his drinking buddy's hobby. This was a guy who wanted a son so badly he didn't let reality stand in the way of naming his daughter Stanley.
It's a freakfest no matter how you look at it. Maybe the birth cert is blank, because The One was conceived by no man, but by the seed of Satan. :-/