How Analytical Models Failed Clinton. Her campaign was so confident in its data that it opted not to do tracking polls in states that decided the election.

Charlie Cook reports:

It was the in­di­vidu­al state polling that badly missed the mark. In Wis­con­sin, Clin­ton led in each of the 32 pub­lic polls from mid-Au­gust on. The fi­nal Mar­quette Uni­versity Law School, gen­er­ally con­sidered to be the most re­spec­ted in the state, had the Demo­crat up by 6 points. She lost by eight-tenths of a point.

In Pennsylvania, Clin­ton led in 37 out of 38 polls be­gin­ning in early Au­gust. CNN’s last poll had Clin­ton up by 4 points, the fi­nal Quin­nipi­ac poll had her up by 5 points, and the Real­Clear­Polit­ics av­er­age had her up by 1.9 per­cent­age points. She lost by eight-tenths of a point.

In Michigan, Clin­ton was ahead in 25 out of 26 polls taken from the be­gin­ning of Au­gust on. The De­troit Free Press’s last poll had her up by four points, and the Real­Clear­Polit­ics av­er­age had her up by 3.6 points. She lost by two-tenths of a point.

Just a reminder as we head into 2018.