Since when?
Kindly point out an instance where I have used polling results to prove that something is a good idea or not. The very thought is laughable.
Polls show what people are thinking about something. If the issue is "what do people think about something," polls are a useful input. Questions like "how do you feel about the economy/Iraq/whatever."
They are not useful for questions like "is this right or wrong," or "is this true or not," and sure as hell I don't let them tell me what I think.