How to understand "stunt double" in this context? Read an old news, and got confused by the phrase "stunt double". Here's the context: "Although neither he or the president landed any knock-out blows, Mr Romney appeared both more relaxed and more focused; the president seemed listless, rambled in his answers and seemed unable to make the case for his own re-election. One usually well-disposed analyst wondered whehter a stunt double had been sent in his place. Mr. Romney needed a victory..." Thank you.