Mr. Obama was making a point about civility in Washington and the ability to "disagree without being disagreeable" when he brought up the belief held by some that he was not born in the United States (a claim that has been widely shown to be false).
"Now, I am the first to confess I am not always right. Michelle will testify to that," Mr. Obama said. "But surely you can question my policies without questioning my faith, or, for that matter, my citizenship."
There was laughter and applause in the room after the remark. It's one of the few times the president has addressed the claims, which has spread over the Internet and been taken up by a group of Obama critics known as "birthers."
Watch the video at left.