This is understandably causing some panic, but it’s probably not deserved. As The New York Times wrote last week, post-convention polling does not have a very good historical track record of predicting the course of the general election:
History suggests that in the short periods after the conventions, the polling average can often move away from the final result, not toward it. That’s because polls taken in the middle of the convention are often unreliable: Gains made by the party’s nominee can often be short-lived.
In 2000, for instance, both Al Gore and George W. Bush got 8-point bounces in polls conducted by CNN.
Still, many are pointing out that the election, which looked like it could be a Clinton landslide in June, is now pretty close. Here’s Nate Silver, articulating the new conventional wisdom about the race:
Of course, after missing the Trump phenomenon in the primaries, Nate Silver is the last person who should be on a high horse about the danger posed by Trump. But this does help explain why people are taking Trump’s chances of winning so seriously: Many who underestimated Trump last fall are making sure they don’t make the same mistake this time around.