One may vote for up to three options, as obviously there's more than just one thing responsible for the falling apart of the Democrat party.
I happen to believe the Democrat party is going to survive its current civil war, although I don't want to speculate in how good of a shape it's going to be. It'll pull through, it'll survive to threaten the Constitution and our rights and liberties for quite a while yet.
But in case I'm wrong--and I've been wrong before--and the Democrat party shatters apart, I'd blame the Bernie bullies for their utter unwillingness to negotiate and compromise with the supporters of the lady.
One needs note that the supporters of Messalina Agrippina don't have to do a damned thing; they can just sit there and twiddle their thumbs, and she's going to get the nomination anyway. They're under no compulsion to negotiate and compromise with the other side, as they've won anyway.
The Bernie bullies on the other hand are in the position of beggars, supplicants, asking that simply out of the goodness of their hearts, the supporters of the lady give them at least a few things, a few scraps.
It'd be wise for the Bernie bullies to take whatever they're offered, with humble hearts and profuse thanks.
If they don't, and run away to start their own party, that might bring the Democrat party down.....and it'd be the fault of the secessionists.