Even if he wasn’t born in HI, if his mother is American, doesn’t that mean he’s a citizen? Of course if it should turn our that he wasn’t born in HI but he has said he was, then he would be proven (again) to be a liar.
Being a citizen is not enough. The constitution requires he be a “natural born citizen”.
I adopted three kids from other countries, who are all citizens. However, none can become President. I’m not sure whether being born of a citizen on foreign soil qualifies. It may; I’m just not sure.