Because if you were talking about "The Santa Clause," then this would work. Otherwise, not so much. Remember the uproar over Dan Quayle misspelling potato as "potatoe" when it was spelled that way on the card provided to him? Granted, this isn't the President's personal error, but it's still a really stupid mistake. And consider if this had happened to the George W. Bush White House.
This mistake would be EVERYWHERE in the media, and yes I can say that based on past performance by the MSM.