This law states that, in any given political debate, the likelihood that one participant will refer to another as unamerican
increases as said participant runs out of valid arguments.
Named for Fox News.
Fox's Law in action:
Person A: "I disagree with the war in Iraq and would like our troops to come home."
Person B: "That's unamerican!"
Person C: "I think everyone should have access to affordable medical care."
Person D: "That's unamerican!"