Actually, until his actual citizenship status is know by documentation, no one knows for sure what his status is. He could be a non-US citizen, there are several possiblities.
Probably someone has already answered this but just in case they didn’t, here are a couple:
1. If he was born in Kenya and his father is actually 0bama Sr (legally he is the father at this point), then he is not a US citizen unless he got naturalized at some point.
2. Lolo Soetoro adopted him and his US citizenship may have been renounced at that point, so he would not be a US citizen unless he naturalized at some point.
3. He may (most likely did) use a foreign passport after the age of 18 and/or 21, which would be an act of renouncing any US citizenship he may have held at that point.
No evidence has been found that he ever became a naturalized US citizen, so in truth, until his personal documentation is out in the open, all bets are off as to what his legal citizenship status really is.
Nicely stated...