in order to win, sanders has to have an outright majority going in. he can't give the party any opportunity to overturn the results, because they will, if they can.

and, in order to do that, he had to block warren at the start. he had to stop her from gaining any traction at all.

but, he's run an aimless campaign that allowed the media to prop her up, while he campaigned in areas he can't actually win in, and chased demographics that are either out of his reach or too marginal to really matter. and, she's managed to undercut him through his own incompetence.

she still can't win so long as biden is there. but, she can - and will - run interference long enough to give it to biden.