538 What The Hell Is Happening With These Alabama Polls? [View all]

[Quixote1818]

Snip

In other words, SurveyMonkey’s raw data was showing a much more purple electorate than the solid-red one that you usually get in Alabama. If that manifests in actual turnout patterns — if Democrats are more likely to respond to surveys and are more likely to vote because of their greater enthusiasm — Jones will probably win. If there are some “shy Moore” voters, however, then Moore will probably win. To make another generalization, traditional pollsters usually assume that their polls don’t have partisan non-response bias, while automated polls (and some online polls such as YouGov) generally assume that they do have it, which is part of why they’re showing such different results.

Because you’ve read so much detail about the polls, I don’t want to leave you without some characterization of the race. I still think Moore is favored, although not by much; Jones’s chances are probably somewhere in the same ballpark as Trump’s were of winning the Electoral College last November (about 30 percent).

The reason I say that is because in a state as red as Alabama, Jones needs two things to go right for him: He needs a lopsided turnout in his favor, and he needs pretty much all of the swing voters in Alabama (and there aren’t all that many of them) to vote for him. Neither of these are all that implausible. But if either one goes wrong for Jones, Moore will probably win narrowly (and if both go wrong, Moore could still win in a landslide). The stakes couldn’t be much higher for the candidates — or for the pollsters who surveyed the race.




https://fivethirtyeight.com/features/what-the-hell-is-happening-with-these-alabama-polls/