True, but it was also just Trump +9 then.
Tennessee was alongside the Dakotas for the largest polling miss in 2016. The final RCP average was only Trump +10 or +11 (I think RCP even had it just Likely R), when the result was Trump +26.
Not many polls had Lee winning by 21 or Blackburn by 11 in 2018, either.
The margin isn't the issue here. Yes, the 2016 polls had lower margins for Trump but Hillary's numbers were right, all between 31-36%. No doubt Trump will win by much more than 9 points but if Biden is truly around 42% that's significant.
