Ambinder assures us that Obama is simply "tired, nothing more." I guess he was also pretty tired last week when he didn't know what month it was, or how many months were left until the election (he thought it was March and that there were nine months left until November). If McCain made these kind of mistakes he'd be crucified, but Obama...he's just "tired."

Allahpundit offers a more compelling explanation: "Dude’s lost his bearings."