Why is the law of large numbers important understanding public opinion

The law of large numbers tells us that experiments with a large number of observations or participants, tend to have results that are close to the expected values: the statistical mean.

This law is important to understand public opinion, because it can explain why, after surveying a large number of people (remember, this law only applies when a large number of subjects are part of the experiment), the result: the public opinion, is close to the values that were expected at first.