Actually, if you go back and look at the polls they tell a different story. She rarely got out of the margin of error in her lead against him.
Especially after Comey's little grand stand attempt.
https://www.realclearpolitics.com/epolls/2016/president/us/general_election_trump_vs_clinton_vs_johnson_vs_stein-5952.html
The polls weren't wrong.
We were reading them wrong.