If the Rats simply ignore Bernie's voters by inserting Biden in when Hill washes out (for whatever reason), Bernie's voters may indeed turn out for Trump to pay the Rats back.
Agreed. Bernie is more successful than they had planned. He will demand a lot in return for support of the Dem ticket. He presents a similar quandry for the Dems as Trump does for the GOP. How do prevent the alienation of their supporters in the General Election?