Polls are important. You see a lot of them during a campaign season. The question is, what do they really mean?
The quoted margin of errors are large and significant. And, the real error is much larger and more significant than the quote margin of error!
Yet, despite this margin of error and the daily fluctuations, polls are a very meaningful source of information in understanding and predicting an election. You just need to be clear on what a poll means and how best to use it.