I think Bernie will harder to beat than any of the other Dims. I'mm not sure why Rs want so desperately to run against Bernie.
I don't think pubbies want to run against Bernie but this is just to cause chaos, remember Operation Chaos that Rush started years ago?
The dims can't let Bernie win the nomination and they will do all kinds of chicanery to keep that from happening, Bernie bots will come unglued.
The dims could end up with a brokered convention ticking off many dims who will stay home in the General or may even vote for Trump.