That isn't motive.<quoted text>
Certainly, allow me.
If you are born there, you are a son of the soil, as in Kenya. If not, you are a son of the soil where you were born. In Obama's case that would NOT be Hawaii where there is no valid birth certificate proving that imaginary birthplace.
If he was Kenyan, he was still an American citizen via his mother.
The only reason possible for your whole birther scenario is to make him appear "naturally born".
The only benefit "naturally born" gives you is the ability to run for President.
So, his mother must have known he would be running for president in order for any of the birther story to gel at all.
You still have no motive. He was already entitled to citizenship. EVEN if born on Neptune.
So... why the ruse?
That is motive. It is generally what makes conspiracy theories work. You are still holding an empty bag.