Following major heart surgery, and realizing he's been stuck at 20% in the polls forever, 78 year old Bernie Sanders follows the advice of his doctors and drops out of the race before the next debate.
On Oct.31st, folllowing the indictment of 16 Obama administration figures for SpyGate, as well as his son Hunter for RICO, FARA and moneylaundering Biden announces that he is suspending his campaign.
Warren, who has been holding at a steady 25% sees a pickup , but surprisingly the second tier candidates Buttigeig and Yang and Gabbard all pick up big chunks of the roughly 50% of the available vote that was being locked down by Biden and Bernie.
The Democrats come into Milwaukee for their August convention with no candidate having the majority of delegates. The first round voting is inconclusive, and the second round, which includes by DNC rules the 500+ super delegates also fails to reach a majority for any candidate.
... Hillary on Round 4.
I think your crystal ball is accurate
Or, Bernie hangs on and with Trump running unopposed (for all practical purposes) Republican and Independent voters hand Bernie Alabama, Arkansas, Colorado, Georgia, Illinois,Indiana, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, North Dakota, South Carolina, Tennessee, Texas, Vermont, Virginia, and Wisconsin through the open primary system. The Democrats (stuck with Bernie) attempt to oust him once more at their convention and shatter their party.
Stents are not major surgery and many people are discharged the next day. His doctors will advise him to be back to work in two to four weeks at most. However, his campaign will have lost any momentum and many supporters may think he is too old and frail to continue supporting him.