This is what we're looking for in a potential win:
He won every single county in 2006. Of course, I know that Tennessee has moved to the right since then, but I can see him easily doing better than this map.
My above map was built off of a composite of his 2002 gubernatorial race, the 2006 Senate race and 2012/2016 presidentials (plus a bit of subjective gut instinct): basically everything either somewhat recent or somewhat competitive. He's definitely not going to pull 70% in the Senate race - and even if he did, the map would look quite a bit different than his win in '06 I imagine.
The GOP counties aren't as terribly unfavorable to him as they look in that map: basically Bredesen is getting around 42% of the vote in all of them combined (and 60% in the Democratic counties).
How did you make this map?
A few open tabs, MSPaint, a few different spreadsheet formulas for different types of counties. 
Like I said above, I used those 4 relevant elections as data-points to compile the results.
Bredesen should win Lake County, no?
