I think Bill Clinton as the VP candidate would strengthen the Democratic ticket.
I am aware that the 22nd Amendment prevents him from being elected as president again.
May he now serve as V.P.?
This would be a horrible idea for lots of reasons.
1) Bill Clinton was a controversial president. Imagine having a debate about Monica Lewinsky in this age of #MeToo (not to mention Juanita Broaddrick who accused Bill Clinton of raping her).
2) Joe Biden promised to nominate a woman.
3) Joe Biden needs to nominate someone under 70 (Although, I would love to see Jimmy Carter in the administration again.).
4) Most Americans (myself included) cringe at the idea of another Clinton in the Whitehouse.... ever.