Also, the race will feel different it’s really down to one left candidate (Sanders) against three to four center-left candidates (Biden, Bloomberg, Buttigieg, Klobuchar). The debates have all kind of featured Sanders/Warren defending more liberal ideas while other candidates attack them. That environment will be different (worse for Sanders, in my opinion) if Warren is either off-stage or if she is on stage but basically been ignored by the moderators because she has almost no chance of winning.
