Public opinion is seldom clear. This is demonstrated by the frequency with which pundits and pollsters—who spend their careers studying public opinion—are completely mistaken about the result of matters such as elections and referenda, which are the subjects of intense scrutiny. There are plenty of recent examples, including the election of Donald Trump to the U.S. presidency, and the U.K. referendum on leaving the European Union, popularly known as Brexit.

There are many reasons for this lack of clarity. One is that small, highly vocal groups can create the impression that they have many supporters simply by the dedication and tenacity with which they repeat their message. The media often show a great deal of bias, so that your view of public opinion would be completely different if your only news source was reading the New York Times from the way it would be if you only watched Fox News. Ironically, however, those sources (such as the BBC) which seek to avoid political bias as much as possible can do much to make public opinion unclear through this very avoidance. These channels, papers and journals will try to balance every opinion with the opposing viewpoint, so that it is seldom clear which of the views expressed enjoys greater public support.