Biden is being setup as the fall guy. All 2016 investigations are leading back to Clinton and/or Obama. Using Biden gives both of them an out. Also the DNC does not want Biden to be the nominee. Once low information voters hear about his Ukraine business, Biden will be gone from the race. Biden is the useful idiot that will protect Obama and Clinton. An added bonus he gives a lot of deep state persons the ‘I was just following orders’ excuse to also get a pass.
^^ THAT ^^