Throwing out a prediction: If the Biden/Harris ticket wins in 2020 and Trump is charged with anything, expect a pardon from the president. People will rage for a bit, get tired, run out of attention span, and move on to the next controversy.
I don't think Biden could do that. It would be as bad as, if not worse, than another 4 years of Trump as president. It would mean that there are no standards by which a president is held accountable, and considering how many lives he has cost and the corrupt things he has done betraying the country, it would make the next Republican presidency that much worse.
Trump is going to get screwed anyway, even if Biden would step that low (he'd risk alienating all the progressives, I doubt he's dumb enough to do this) Trump would still have to answer to the New York DA.
