All Romney did was directly quote what Barack Obama said.
Since when has quoting a man, providing the full context of his remarks, and then sitting back to watch the fireworks constitute slander?
Well, it doesn't - from a Western point of view.
But from an Eastern point of view, it's an entirely different matter.
From the Sunni Muslim Sharia law manual, Reliance of the Traveller:
r2.2 Slander (ghiba) means to mention anything concerning a person that he would dislike, whether about his body, religion, everyday life, self, disposition, property, son, father, wife, servant, turban,