The US *allows* dual citizenship, but doesn't recognize it. As far as US law is concerned, you are a US Citizen or you are not. But they do allow for it under some circumstances. They certainly don't encourage it. Divided loyalties.
"Divided loyalties" is what the requirement to be a natural born citizen is all about in the first place. After all, who cares if some baby is adopted from Uzebekistan, when she is only a few months old, and never knows anything but being an American.
But that is not the case with Barry. He was clearly old enough to remember being Indonesian, and seems to identify with being African, more than being American. Not someone I want as the Commander in Chief. Heck not someone I want as a fuel handler on an air base in the interior of Alaska.
These are all political, rather than Constituional, issues. Obama meets the Constitutional requirements for being President, but that's just the first step. In my opinion, he is unqualified in every other way to be President.