Public opinion becomes politically relevant when it influences the decisions of government.
Some functions of public opinion are as follows:
1. It directs government to know what the public think about its policies and actions.
2. It helps the government to know the needs and aspirations of its citizens.
3. It brings about the formulation of policies and taking actions that are in the best interest of majority of the citizens.
4. It provides valuable information about those contesting elections. This on condition that the election is free and fair.
5. It helps the voters to cast their votes for popular candidates.
Public opinion is then said to be relevant if it causes any or some of the points raised above to take place especially number 1,2 and 3 points.