Dig up the corpse or get a family member’s DNA to first check for parentage - then go from there. If a substantiated obama, then the Kenyan birth makes all the more sense.
You will never get Obama’s DNA to match.
Except for one notable recent example involving a blue dress.... The SS actually protects the President’s DNA from being taken. Going so far as to take glasses, etc that could be picked up. At least that use to be.
Fears during the cold war started this.