Surveys are integral parts of any political campaign. However, they can be dead wrong as in the victory of the Brexit or Donald Trump. Major events that the polling companies have been unable to predict.
Pollsters sometimes use questionable methods: respondents being paid to lie, biased questions, manipulated numbers.
What are the industry trade secrets?
How are they designed?
Do they actually influence voters and candidates?
Do they jeopardize our democracies?