People keep bringing up the issue of citizenship. I don’t think that is the main issue. Obama is a citizen unless he renounced his citizenship after the age of eighteen, but we don’t have any evidence ATM that he did. The question is how does an adoption and citizenship in a foreign country affect one’s natural born status? This is not 100% clear.
Zero was born British, and later spent his years in Indonesia. Indonesia law prohibits dual-citizenship, so he had to lose his British citizenship.
Zero never had natural-born U.S. citizenship status