The Constitution and the applicable Supreme Court decisions would seem to indicate that they are. But let's take a more likely scenario. Two foreign nationals move to the U.S. legally and have a child. That child is born in the U.S., raised and educated in the U.S., attends university in the U.S., never spends one minute living in the land of his birth parents but instead spends his entire adult life in the U.S. Why should that person's loyalty be questioned and he be denied the chance to run for president? What clause in the Constitution or U.S. law or Supreme Court decision supports their inability to be president?
He is a citizen, but not a natural born citizen and could not run for POTUS.
That's my point...you have a perfectly sound case...but, let's suppose in this day and age of multi-culturalism, the child picks up English as a second language with the foreign tongue being spoken at home. The child's parent's indoctrinate him as a foreigner living abroad in the U.S. (this happens regualrly in both Hispanic and Muslim Communities in the U.S.) with allegiances elsewhere. It may be in compliance with the letter of the Constitution as presently interpreted, but I would contend it's inconsistent with the spirit of it, and the NBC clause in particular. It's a dicey argument and I don't pretend to know the answer...I just think the case of our current President begs for clarification as much for the future as it does for the present.