Most of the polls conducted for the 2016 election were within the statistical margin of error, so it's not like the polls were necessarily wrong.
...
...
These polling companies conduct thousands of polls a year. You can look up their records, if they have consistent outliers they lose funding.
In terms of the popular vote, the polls were mostly correct.
The only poll that consistently put Trump ahead of Clinton was run by the LA Times / USC -- I will be paying particularly close attention to their results this time around.