The father must be a citizen, and it doesn't matter where the child is born.
Natural born citizenship is hereditary. Both McCain and Obama could have both been born on the moon, and McCain would still be a natural born citizen while Obama would not.
Here’s what’s going to happen if there’s ever another court case on this: “mother’s a citizen” = “child is a citizen”, regardless of where born.
There are numerous long threads on FR that prove without any doubt that in order to be a NBC a child must have both - citizen parents and be born on US soil.
Please educate yourself on the matter.