It's immediately obvious that the politician

Two men are sitting at a table in a café. At some point, one of them says to the other: “Listen, you’re a politician, I guess?” “Yes. How did you guess?” “Half the answers in your crossword are wrong.” The other man takes a quick look at the first man’s crossword and retorts: “You’ve got half the answers wrong yourself!” “I know, I’m a politician too.”