>>But what about his being born in Canada? <<
The supreme court has never ruled on the natural born citizen clause. It is understood that if a candidate was born and one of their parents are a U.S. citizen, they are a U.S. citizen unless that U.S. citizen renounces their citizenship.
We’re going to be drowning in hooey for a long time. No matter original intent or supposed past precedent, should the SC rule definitively, it will find that there are only two types of citizens, those who are citizens by the circumstances of their birth, and those who require naturalization.