Bad move. Scientists who've studied delusional people will tell you that you don't get anywhere by presenting facts and evidence. Better to pull a Reagan and use jokes and feigned agreement to pull the steam out of the birthers.

Possible presidential response to questions about his birth:

"I don't really remember my own birth, so I can't say where it was either way. But I'm told that angels sang."

"I'd like to think I sprang from the head of Zeus."

"I was born in a little Austrian town, the son of a policeman, but through weightlifting and will, I became as American as anyone else."

"The people who write me letters in the White House assure me that I'm the spawn of Satan, and the last I heard, he was living in a red state."