Polling Is a Complex Process

George Gallup was hired by a New York advertising agency to find out people's opinion of consumer products like toothpaste and soft drinks. At this time, polling was focused on consumer preferences, not politics. But asking people about their political views is a lot more complicated than asking them about toothpaste. One of the reasons for pollsters' failure to predict Trump's election in 2016 is that they didn't ask enough white, non-college educated voters.