Bold prediction: Democrats pick up 4 seats AZ,NV,TX and TN while losing none. Democrats win the Senate 53-47. In waves the vast majority of toss up seats fall one way. Look at 2006, 2008 and especially 2014. I remember 2006 well, Democrats were at a worse deficit then they only had 45 seats. People said Democrats had no chance to win the Senate, how could they possible knock off a titan like George Allen in solid Republican Virginia? The wave brought in a lot of surprise victories.
This isn't my prediction (yet) but I do agree that folks too quickly dismiss the possibility.
Polling and fundamentals (mostly) favor Bredesen. Tilt D.