They deliberately act incompetent. And they have the same interests as the other side of the uniparty since they have the same donors and are ment to serve them, not the public.
And it’s not their own controlled opposition Bernie that they want to shut up or furiously andsuddenly competently work to get off the ballots, but real left 3rd party candidates.
They have their Bernies and squad members for the sole reason to keep their voters running away from them.