Joe Biden is indeed senile and everyone knows and agrees with this so why is the DNC saying that there will be no debates during the Presidential primaries basically saying that they full endorse his presidential ambitions. I am sure that they find Biden easy to control because his reasoning is not all there. they finally have a stooge they can control.
I would personally find it to be very strange if in the end there is no democrat primary. At least someone in the party must not agree with the candidacy of Joe Biden. It would not be democratic at all.
Like here in my country, where there is a authoritarian party in power and noone dares to talk about primaries to challenge the leadership of the current president.
In that sense, at least the Republican party offers a big variety of options, regardless whether Trump is leading the polls or not.