While the fact that the document is forged suggests that he is not a natural born citizen. For what other reason would they offer up a forged CoLB? But it's not quite "proof". For that you need to get a CoLB directly from the State of Hawaii, and better yet a copy of the Certificate of Birth, aka "Long form" or "vault" certificate.
That's all we really want, and there is NO reason it cannot be provided to a court or election official.
He's got high-ups covering for him--case in point he's appoionting DCI John Brennan who as CEO The Analysis Corp employed the contractor who accessed the Obama passport file.
No doubt to check what was there, remove or modify anything inconvenient, insert whatever was deemed necessary.
The stonewall and slow-roll in responding to repeated requests indicates it isn't there and will have to be manufactured.
No doubt a passable instrument can be created, and provided to someone who can be informed that he or she really doesn't want to get on the wrong side of Mr. Cold Eyes the Cypher Sent to Save You.