Hmmm. What were the odds called by the mass-media (and the betting markets) that Hillary would win, in late October of 2016?
For someone that is usually so pragmatic I'm surprised to see you going down the poll-denier path. There were plenty of pundits saying Trump was dead in the water, but that didn't reflect the actual numbers and really anyone that says they know for certain what the outcome will be before election day is either a liar or a fool and should be ignored.
The final 2016 betting markets and most models had Trump between a 2-1 and 3-1 underdog to become president.
The final national polls on average had Clinton with a 3.2 point lead and she ended up receiving 2.1% more votes.
National polling was accurate, but some of the state polling wasn't even close. Wisconsin and Michigan were off by a sizeable amount. There's no doubt he's down in the polls, but I don't think it's impossible for Trump to trip towards the finish line like he did in 2016.