There must be at least one charismatic and sane democrat in the party?

They would just ratfuck them again like they did Bernie (who also decided to fold completely to Biden and is even now mirroring his stance on Palestine.) If someone decent somehow manged to slip in, they would likely self sabatoge the same way Jeremy Corbyn was betrayed in the Uk. This is assuming the democrats didn't just straight up pick their guy for the primary anyway which the DNC (as a private organization) is legally allowed to do. Shits fucked.