So not really a surprise.
Try to look beyond the state and look at the trend.
Exactly! Hillary was down after the GOP convention with 11% undecided. Mid September, after a month of problems for Trump, she was up by about 7 points, Trump was down 2, and undecideds were down 3.5%. A month later, after 2 of the debates, Clinton was back down by about 6 points while Trump surged by 9 and the undecideds lost another point. I’d say it’s good news!