Considering that Obama spent a lot of time with Davis, and looked upon Davis as a black role model, it's hardly surprising that he (consciously or unconsciously) picked up on Davis's speech patterns.
That may be but I think there's more to it. The eyes, the somewhat pointy ears, the form of his upper lip in the center, the weird pouch under his bottom lip
all match FMD. The history of the Dunhams and FMD along with FMD's self-documented sex addiction, Stanley Ann's nudie photos, Barry's "Pop" poem all suggest strongly that there was a multi-generational carnal association between FMD and Stanley, Stanley Ann and little Barry - a sordid origin story if ever there was one.
The Malcolm X thing is a red herring based on the similarity of the chin but certainly Barry's chin is the very prominent Dunham chin and there is no known contact twixt Stanley Ann and MX.