Most people recognize a poll as a sample of how people in the population at large think about a certain issue, but is there more to it than that? Often, seeing a poll may very well change our opinion on a subject. For example, if you see a poll that suggests a large majority supports the minimum wage, that may influence you to have a favorable opinion on the matter. We think to ourselves, well, if most people are in favor of it then I should probably be in favor also.
Politicians and political activists are not ignorant to this affect and they seek to use it to their advantage. Poll questions can be asked in manipulative ways in order to extract the desired result and the data can be represented however the pollster chooses. When people see the results their opinions are influenced in the direction the pollster hopes it will go.
A poll can also be affected by how it is conducted and who is polled. For example, if you want to show that one candidate is doing better in a political race than another you might actually poll more people who are members of that particular candidate’s party in order to skew the results the way you want.