This is why Democrats are circling the wagons around Hillary. They would be stuck with Biden. Then there’s no one else.
Eight years ago Hillary Clinton was polling even better than she was now. Her chance was then. A younger, more charismatic, more electable candidate emerged. History will undoubtly repeat itself, but we can always hope that this time her followers will be so bent out of shape that they create a lot of bad will in the general election.
Last time the Clintons went into hiding for three months while they contemplated the prospect of one last chance in 2016. This time there will be backup plan.