It may be absurd, but it is the law, i.e., jus solis.
American citizens do not, of course, need any sort of visa to be in their own country. So, what kind of message was being sent? Was it that legal visitors with visas were classified differently than other visitors who had not yet bothered to pick up their visas?
Since this is all based on administrative decisions, and not those of the judiciary or Congress, it's entirely possible that ICE and State Department could be directed by Congress to cease and desist from making the birthright citizenship decision, and to WITHDRAW all previous decisions.
After all, that's what's done when virtually any administrative decision is reversed or withdrawn. Life then goes on as if it had never been made ~ IRRESPECTIVE OF COST OR CONDITION of those affected.
That'd probably strip the Democrat party of 30 million votes!
Oh, lest I forget, this would definitely call into question the current Romney’s own privilege of running for President. After all, if his grandpa wasn’t really a citizen, and his dad wasn’t really a citizen, then maybe he’s not really a citizen.