Might need an exciting VP although I have no idea who that would or could be. I would just hope people learned their lesson from 2016 even if they disappointed that it isn't Bernie or whoever. Small step forward is still way better than a giant step back.
If Biden does win I hope he just runs away with it right from the start.
All they need to do is keep the messaging on economy and healthcare. If there's not a major economic downturn between now and then, they need to poke holes in the GOP "good for the economy" myth. If middle class people go to the polls thinking "well, Trump's good for the economy", the Democrats lose.
This can't be Bernie's equality for all socialism. It has to be centrist stuff that used to be the bread and butter of the Democrats.