True, but the way they are conducted is "Are you going to vote for Clinton or Trump?" More people answered Clinton, so it skews the polls in her favor and in general Clinton voters were prouder of their choice so more likely to answer which further skews the polls but again she still had a 30% chance of losing (which she did) even with that skewing.

And yes I think Huffpost can pretty safety be tossed out on any sort of political polls (Same goes for things like Fox News, Brietbart, ThinkProgress, or any of the other hyper partisan news agencies), I was referring more to actual statistical analysis places like 538, who themselves did a pretty good breakdown on how the polling was fine for the most part, the reporting on the polling was what was less than steller, good read if you are interested.

https://fivethirtyeight.com/features/the-real-story-of-2016/