Hawaii became a US state on 21/08/1959 Obama born in Hawaii on 04/08/1961
So going by the below he's a US citizen.
The 14th Amendment to the United States Constitution provides that all persons born in the United States and subject to United States jurisdiction shall be citizens at birth. What is important is where the child is born, not the citizenship or residence status of the parents. Thus, a child born in the United States of illegal alien parents is still a United States citizen at birth. The only exception is that the child must be subject to the jurisdiction of the United States. Therefore, a child born to certain foreign diplomats or sovereigns are not US citizens at birth, since they are born while their parents are not subject to the jurisdiction of the United States since they are in the US as representatives of foreign governments.
