Excellent series of articles on where and how the US presidential election predictions went wrong (and right).
Of note:
Another myth is that Trump’s victory represented some sort of catastrophic failure for the polls. Trump outperformed his national polls by only 1 to 2 percentage points in losing the popular vote to Clinton, making them slightly closer to the mark than they were in 2012. Meanwhile, he beat his polls by only 2 to 3 percentage points in the average swing state.3 Certainly, there were individual pollsters that had some explaining to do, especially in Michigan, Wisconsin and Pennsylvania, where Trump beat his polls by a larger amount. But the result was not some sort of massive outlier; on the contrary, the polls were pretty much as accurate as they’d been, on average, since 1968.
Why, then, had so many people who covered the campaign been so confident of Clinton’s chances? This is the question I’ve spent the past two to three months thinking about...