The Indians in the Lobby - S3-E8
Factual error: When President Bartlet is on the phone with the butterball hotline, he claims to be from Fargo, ND. Charlie tells him the zipcode of Fargo is 50504. Fargo has 13 zip codes assigned to it. None of them are 50504. They are all beteeen 58102 and 58126. (00:28:05)
Chosen answer: A really annoying innate lack of sense. My friends and family say the same thing all the time, and I'm endlessly trying to correct them. I think people just don't know any better and (ironically) couldn't care less that they're speaking incorrectly.