After every debate the great question is, Who Won? But nobody ever defines what winning means. Therefore, any answer is meaningless. I can think of several possibilities:
1. X was the better debater -- better informed, all factual claims were accurate, more articulate, logically compelling arguments, and the like.
2. X had the sharp zingers that will dominate the news the next day.
3. X won more voters for his/her candidate than the other.
4. X was more personally engaging, made better contact with the audience.
5. I preferred candidate X for my own reasons.
6. A combination of some or all of the above.
7. None of the above.
Next question: Are we safer now than before 9-11? Adapt the above argument to this one, i. e., meaningless without definition.