That sounds impressive, until one considers that RealClearPolitics (my former employer), nailed 49 states. Their prediction only got Florida wrong. They don’t use magic sauce; instead, they do a simple (though statistically incorrect) arithmetic average of polls. But it’s good enough. Occam’s Razor would advise us to accept the simple RCP model over Mr Silver’s fancy model. If the more complex model does not yield substantially better results, then perhaps the added complexity is nothing more than smoke and mirrors.
Fast forward to 2016. Mr Silver predicted, with an absurdly precise 71.4% chance, that Mrs Clinton would take 302 electoral votes and beat Mr Trump by 3.6% in the popular vote. He was wildly incorrect. (As of the writing of this article, Mr Trump will win 306 electoral votes but will lose the popular vote by merely 0.2%.) Even worse, Mr Silver got several key states wrong: He predicted that Clinton would win Wisconsin, Michigan, Pennsylvania, North Carolina, and Florida. In reality, Trump swept all of them.
RealClearPolitics, with its simple model, was also wrong but much closer to the truth: It predicted Clinton wins 272-266 with a national margin of 3.3%. Furthermore, it correctly predicted that Trump would win NC and FL.