You don’t know which polls? If you truly wanted to see that nothing would stop you from using Google to check yourself.
As for proclamations that Hilary would definitely win anything, I don’t know of any source outside of the alternative facts media or White House propaganda that would proudly make such claims that could be disconfirmed by reality.
What is lost on the lay person is that a prediction does not mean a guarantee. There is a statistical margin of error that all predictions must have, and the are unique errors due to biases dealing with people. (Response bias, selection bias, ppl just flat out lying) No one who understands a forecast would think it was a guarantee, but that doesn’t mean the average person at home gets the difference.
Your original assertion is that the speculators did such a horrible job and mention Michigan. 11k votes decided the state for Trump. After googling (you should try it) I see polls predicting Hilary with 3.4% and a margin of error of — get this — 4%! Your homework assignment is to evaluate this prediction and see how horrible it did.