From a Politico article titled “How much do voters know?” by Alexander
Burns:

“The first lesson you learn as a pollster is that people are stupid,”
said Tom Jensen of Public Policy Polling, a Democratic polling firm. “I
tell a client trying to make sense of numbers on a poll that are
inherently contradictory that at least once a week.”

Full article at:

http://www.politico.com/news/stories/0312/73947.html

Message to Tom Jenson:
It’s not so much that people are stupid as it is that Tom Jenson is ignorant of the cognitive underpinnings of response methodology and filling in his gaps with unnecessary condescension. Truly, all survey researchers deal with these contradictions. We might be able to garner more consistency in our response sets if we could instead survey computers or robots, but, alas, that’s not why we conduct surveys.