Where does the Constitution say that?
It has been argued that the location in Panama was considered at the time to be American property/soil?
But it was not. The 14th Amendment didn't apply there in that if a Panamanian couple gave birth in the Canal Zone their child was not a U.S. citizen. Of any kind. Besides, McCain wasn't born in the Zone.
Recall the fuss when Carter gave the Panama Canal away? He could not have given it away were it not ours to give away. Right?
The U.S. had control over the zone through treaties signed in 1903. Carter gave up that control. The Zone was never considered part of the U.S.
However, upon proper consideration by our founders, under the circumstances of McCain’s birth, I am covinced they would have amended the Constitution to exempt US military as well as US citizens serving American interests abroad.
They didn't need to. Congress has the authority to decide who is a natural born citizen and who is not. McCain was a natural born citizen because the law said he was.
Jindal on the otherhand: If both his parents, were at the time of his birth on US soil, were themselves US citizens, then he would be a natural born citizen.
They were not. Neither had been in the U.S. long enough to qualify for citizenship when Jindal was born. But per the 14th Amendment Jindal is a natural born citizen because he was born in the U.S.