Actually, you're wrong. Public figures can be defamed if there provable malice in the inaccurate statement. For instance, I can't print that while running for President Hillary Clinton's fainting spell was due to her being drunk (possible, but defamatory when provably wrong) whereas it wouldn't be defamation to print that Hillary Clinton is the head of a coven of witches (impossible no one would believe it...I hope... maybe I'd better retract that).