IIRC, the whole ‘his mother is an American’ meme only started since Trump brought up the issue three weeks ago. Before that, they barely touched any of it, except to cast those who questioned his eligibility as kooks.
Here ‘tis:
Dear Mr. Davis:
The term “natural born citizen,” as specified in the U. S. CONSTITUTION as a necessary condition of eligibiity for election to the office of President of the United States of America, rests on two definitional bases, to wit: (1) birth in the territory of the United States of America, and (2) both parents being citizens of the United States of America.
There are sound historical reasons for asserting these conditions, as a bit of research into the Laws of Nations would reveal to you. The second stated qualification is imposed for the purpose of avoiding election of a chief executive holding divided national loyalties. The present case of Barack Hussein Obama/Barry Soetoro amply demonstrates the necessity of that qualification.