Not to anyone with an ounce of integrity or more than five functioning brain cells (which of course, rules out Biden himself, on both counts). Unless you mean 20 for Biden and 80 for Trump?
You’re not understanding. The premise is “how can the Democrats cheat the totals without arousing suspicion?” The answer is to make one of every five ballots for Trump. It means they have to produce more overall ballots and maybe they’re afraid of more union overtime but when inner-city votes say 20% backed Trump, the counters can say “See? it’s plausible to believe that 80% voted for Biden.”
But, you know if they get away with this, why should they care that everyone knows they cheated.