F. RENUNCIATION FOR MINOR CHILDREN
Parents cannot renounce U.S. citizenship on behalf of their minor children. Before an oath of renunciation will be administered under Section 349(a)(5) of the INA, a person under the age of eighteen must convince a U.S. diplomatic or consular officer that he/she fully understands the nature and consequences of the oath of renunciation, is not subject to duress or undue influence, and is voluntarily seeking to renounce his/her U.S. citizenship.
G. IRREVOCABILITY OF RENUNCIATION
Finally, those contemplating a renunciation of U.S. citizenship should understand that the act is irrevocable, except as provided in section 351 of the INA (8 U.S.C. 1483), and cannot be canceled or set aside absent successful administrative or judicial appeal. (Section 351(b) of the INA provides that an applicant who renounced his or her U.S. citizenship before the age of eighteen can have that citizenship reinstated if he or she makes that desire known to the Department of State within six months after attaining the age of eighteen. See also Title 22, Code of Federal Regulations, section 50.20).
http://travel.state.gov/law/citizenship/citizenship_776.html
Wow, thanks for posting that, I didn’t believe it was that way.
The questions then are, did Barack renounce it (and I think he would have), and never try to get it reinstated within the 6 month window after he turned 18.