In his remarks to the House Democratic Caucus (the White House website called it “The House Democratic Congress” – talk about a sense of ownership), the president said:
I have the great pleasure of having a really nice library at the White House. And I was tooling through some of the writings of some previous Presidents and I came upon this quote by Abraham Lincoln: “I am not bound to win, but I’m bound to be true. I’m not bound to succeed, but I’m bound to live up to what light I have.”
The book he was consulting may have been They Never Said It, by Paul F. Boller and John George. If so, he missed what they said about the Lincoln passage: “This sounds like Honest Abe, but honesty compels admirers of Lincoln to admit that there is no documentary evidence for the statement.”