It's way too early to be taking polls seriously. But Bredesen did win two state-wide elections during a period when Tennessee had rapidly been turning Republican. He isn't going to be an easy person to beat. Blackburn will have to run a tight, focused, error-free race.
The focus would need to be against Schumer and Pelosi. No matter how “moderate” Bresden claims to be, he’s running to help Schumer and Pelosi control the agenda and that certainly isn’t “moderate.”