They actually do have a prediction engine. The Clinton Campaign called it ‘Ada”. It predicted Trump would win. They refused to accept this. I believe this happened more than once. The problem likely was the GIGO effect. They didn’t know a thing about the Trump voters.
https://www.washingtonpost.com/news/post-politics/wp/2016/11/09/clintons-data-driven-campaign-relied-heavily-on-an-algorithm-named-ada-what-didnt-she-see/?utm_term=.a4940952c0e4
Some discussion here:
https://news.ycombinator.com/item?id=12926082
Most people think I’m kidding.
I’m not.