First, show me the relevence to Obama being born in the US. Let's try to limit the diversions a little.
Don't change the subject, the conversation was about the power of Congress to determine how citizenship is conferred. Where was Congress given that power. It's relevant to citizenship if he was not born in the US, and could be relevant if he was born in the US of a non citizen father, which he admits to. Not to citizenship of course, but to "natural born citizenship".