I'm thinking it's a PP from an original, BUT he does sign copies of his books if you send one to him.
I got one signed awhile back (I tried a baseball, but his staff sent it back with a letter saying he only signs his books).

Hi theartist29 :)

Thank you for your feedback {up} Great Success :P

You have been added to the list for the $10 gift certificate.

{star} [url=http://www.fanmail.biz/57896.html]Jimmy Carter[/url] on Fanmail.biz | [url=http://www.fanmail.biz/feedback/Jimmy_Carter.html]Previous Feedback(s) Received[/url]

Fanmail 8)

Sent an email to the Carter Center http://www.cartercenter.org/ on Feb.3rd & received this (I believe it's a PP) on March 21st.
[url=http://smg.photobucket.com/user/theartist29/media/Jimmy%20Carter%20autograph.jpg.html][img]http://img.photobucket.com/albums/v293/theartist29/Jimmy%20Carter%20autograph.jpg[/img][/url]