Why were they wrong? That question is the most important thing and something you should be asking. That's what science actually is. Science isn't about being right or knowing everything. Science is about correcting for errors through repeated trials.

So saying, "the polls were wrong" completely misses the point of polls or science in general.

And to clarify because it's quite laughable how wrong you are. The polls were correct about Trump. Seriously. The polls showed Hillary winning the overall count, which she did. They also showed very close races and gave a margin of error large enough that a Trump victory became a predicted possibility. The polls were right, journalists were fucking retarded though, and they are always clueless about science. Here's another thing, if the only place you get science news from is journalists, then you're clueless about science too. Essentially, only listen to actual scientists about science, people are too uniformed to play the telephone game.

If you followed the actual polls, or Nate Silver's website which continues to be one of the few that understands the science behind polls, you would have seen that while Hillary was more likely to win, Trump had a sizeable chance on election day. And remember, these are probabilities. Predicting Trump had a 33% chance of victory isn't incorrect. It just means if you repeated the day three times, Trump would win one. We are just in that reality. To actually say a poll is wrong, you need to look closer at a lower level, look for the margin of errors, and see how outside that the real world value is. Have you done that?