Please explain the dozens of ways Obama can prove his citizenship without producing a birth certificate.
A passport can be used to prove citizenship, in the absence of a birth certificate, affidavits from older relatives, church records, contemporary census data, post-natal medical records....
Lots of things have been used in the courts and in making policy. There is lots of precedent.
There is no precendent, particularly in using a challenge to citizenship to overturn the results of a completed election.