Why to "someone other than..."? Stanley Ann was young enough when BHO was born, that she could not pass US Citizenship to him, under the law as it existed in 1961. Only if (1) He was born in the US or (2)His parents were not married at the time, would he have been a citizen at birth. Since there are divorce papers that seem to indicate that Stanley Ann was married to BHO Sr at the time of his birth, condition (2) is not satisfied. (Doesn't matter if BHO Sr was not really his biological father).