I don't see Shumer keeping his seat of power, the new class has been very vocal about that. If I were Jefferies, I'd be working hard to show i'm not just the stooge people are making him out to be by promising to actually deal with the problems, not play the 'moving on' card.
Why not Bernie himself? Him or Elizabeth Warren would be great for it. Both experienced and have been wanting to make these changes for years.