“If that weren’t already reason enough for Trump supporters to worry, a poll from NBC and the Wall Street Journal released on Monday put Clinton’s lead at 14 percentage points.”
That was 28 days before the election.
https://www.theguardian.com/us-news/2016/oct/11/election-polling-trump-clinton-lead
Yes, but that’s one poll. Most polls at that point showed the race much closer. The polling average was Clinton +5 at this point. Right now it’s Biden +10.