I’ll give you the simple answer. Surveys!
No, I don’t mean looking at whatever survey happens to catch your eye or tickles your (or your favorite network or blog’s) ideological fancy. I mean, using a system that is powered by old fashioned surveys and making very, very good explanations and predictions based off that. There is someone who has been doing exactly that for several years now and it makes sense for anyone interested in surveys to understand how he is doing that. I’m talking, of course, about Nate Silver at fivethirtyeight.com.
Interestingly, Silver does not actually do a single survey himself. Instead what he has done is build a database of surveys (that contains thousands) and used some simple and clear rules to analyze them. Based on these rules and the statistical models he has built, he is able to provide the best, unbiased view of the race. All this from survey data. How does he do it? Let’s take a look at some (and by no means all) of his rules.