The thing that folks don't want to acknowledge is that Trump brought him up close to winning. Bevin's opponent, was Beshear who was the son of a former governor of Kentucky and Beshear is a huge name in Kentucky politics. This is what won the race for the Dems---name recognition and Bevin unpopularity. You'll notice that the rest of the state went Republican including the first black attorney general who was all in with Trump. By the way, the new Republican attorney general replaces the Dem Beshear who was just elected Gubner.
All of this is fine except you’re missing the point about comparable approval ratings between trump and Bevin.
This was a high turnout election mirroring what enthusiasm we are seeing for the presidential election. The fact that the democrat got so many votes in a red/red state should give you pause because it shows there are a lot of movable Republican voters.