I feel like this could be like MO senate 2016
If polls were correct and Clinton had won Democrats likely would have picked up that seat.
It's astounding how much better of a candidate Jason Kander was than Claire McCaskill. Kander outran the top of his ticket by several points in an R-leaning presidential year, while McCaskill lost (and not in a squeaker, either, but by a relatively clear margin of 5-6 points) in a D-leaning midterm.
If Kander had ran in 2018 rather than in 2016, I think he would have pulled it off. That he came as close as he did in a year that Trump took the state by 19 points is itself very impressive.