Not really...
Final 2016 polling averages:*
National:
Polls - Clinton by 3.3 points
Actual - Clinton by 2.1 points
Comment: Excellent results, well within the margin of error.
Florida:
Polls - Trump by 0.2 points
Actual - Trump by 1.2 points
Comment: Excellent results, well within the margin of error.
Penn:
Polls - Clinton by 1.9 points
Actual - Trump by 0.7 points
Comment: Acceptable results, within the margin of error.
Michigan:
Polls - Clinton by 3.4 points
Actual - Trump by 0.3 points
Comment: Within the margin of error
Wisconsin:
Polls - Clinton by 6.5 points
Actual - Trump by 0.7 points
Comment: Bad results
*Source:
https://www.realclearpolitics.com/ep...tein-5952.html
The link brings you to the final 2016 national polling averages; you may also pull up the state-by-state averages.
Why were a few of states polls off by more than expected? Undecided broke disproportionally toward Trump (polls don't make predictions about undecideds, obviously) and incorrect modeling of demographic turnout. Will this happen again? I guess it depends on who you're backing.