bob,
The definition of Natural Born standard does not include two citizen parents. It is an expression of jus soli not jus sanguinis. Citizenship can be conferred either by being born under the sun (on the soil) or by the blood. We have had Presidents before who had a parent who was not a citizen. Winston Churchill was born in England, that is why he was ineligible. Aside from the very unlikely possibility that BHO was not born in Hawaii is the possibility that he gave up his Natural Born status by claiming foreign citizenship after his 18th birthday. That possible loss of the special Natural Born status is not the same as saying he is not a citizen. He would not have lost his US citizenship when he was taken overseas as a child and the US would not deny him his citizenship just because he claimed a foreign nationality when traveling or applying for financial aide. You only lose your US citizenship if you formally renounce it as an adult or if you take a foreign citizenship to avoid paying US taxes.