For context, this blog post is by Andrew Gelman, a professor of statistics and political science at Columbia University, and one of the people developing the presidential forecast model for The Economist. So he's not a pollster, but he's relying heavily on poll data for making predictions, which is why his particular focus in this post is not just about the ways the polls were off, but how the polls were incorporated into The Economist prediction model.

I would argue 538 made a similar error[1], but unlike Gelman, Nate Silver is a less likely to admit their model was off, and consequently examine/discuss the underlying factors that lead to this issue.

[1] I don't know if error is the right term here, but basically the fact that the actual election results seem to be landing near the lower end of the predicted 95% intervals for both the 538 and the Economist models.