Biden would be the LAST person of the pool of Democrats that I would have picked, but I still think he's way more electable than Clinton. She had a ton of super sketchy baggage that Biden doesn't have (yet anyways).
I have no doubt Trumps base will support him, but I think the people that hated Clinton so badly 4 years ago that voted for Trump, may consider Biden this time around. He's just not as much of a spawn from hell... so that's hopeful.