The State Dept has custody of Obama’s passport records. Rep. Duncan chairs an oversight committee of Homeland Security. Homeland Security is the custodian of America’s immigration records.
Only an immigrant would fake a U.S. birth certificate. Since Rep. Duncan has the means to investigate Obama’s immigration records, why doesn’t he?
Knowing that your knowledge of the State Dept. is extensive, are you confident that Duncan has access to the State Dept. records? The perfidy of Homeland Security, the lies of Napolitano unchallenged by Congressmen who interrogate her but don't frame the inconsistencies in her own testimony doesn't give much confidence. Napolitano denies, and later can't remember, whether there were any Saudi citizens arrested after the Boston Marathon bombing, denying that any Saudis who had never attended the Colleges they used as the reason for their visas were sent out of the country and declared potential terrorists.
If Obama were a natural born citizen that citizenship could not be lost by his naturalization before majority in Indonesia, from the precedence established by Perkins v. Elg - Marie Elg could not have her birthright citizenship, granted by nature, denied by men. That is the difference between naturalized citizenship and citizenship granted by natural law. But if we honor our laws, Obama was a citizen for having been born in Hawaii, a “native-born citizen of the US” but not a “Native” or “natural born citizen”, by the 14th Amendment, but lost it when he was naturalized by Lolo, as I believe you pointed out. He never petitioned for US citizenship after he become an adult (isn't there time specified, six months or so after majority?) So it is possible, though perhaps not relevant, that Obama is not even a legal citizen. Presidents must be natural born, but this administration clearly considers the Constitution a living document, which they can reinterpret at their will.