I’m going to explain why pollsters got the result so wrong in the lead-up to the UK parliamentary general election in 2015, and simultaneously the real reason why parties, or candidates, win or lose. And use this as a basis for predicting the 2016 US presidential election.
Yet again, during the post-mortem of an election, politicians explain why they won or lost (primarily those who lost. Those who won are usually pleased to bask in the glory and relief), and pollsters are scratching their heads to explain why their polling turned out to be so incorrect.
The reasons both give for their failure - of either type - are usually blaming various factors supposedly outside their control - usually nefarious behaviour of the other party / candidate, or broader circumstances over which they had no control. But if we take a look at both elections and polling predictions - both pre-voting and exit polls - superficially there doesn’t appear to be a credibly reliable explanation. The strangeness of polling errors is particularly interesting because at times the polls leading up to an election are wrong, and at times it’s the exit polls that are just as wrong. And it doesn’t happen just in the UK as the same kind of issues happen in the US.