It was the mail in-ballots that allowed Democrats to harvest ballots from people too ignorant, uninterested, or incompetent to vote on their own - the very people who are prone to manipulation and brainwashing.
Zuckerberg paid liberals $500 million to go door to door and harvest ballots. If he offered $2000 to each, that means there was a virtual army of 250,000 harvesters out there. If each collected 50 ballots, that is 12,500,000 ballots - all for Biden. Without the harvesters, Trump won the popular vote by a landslide.
But beyond thst, Zuckerberg focused his army in swing states. So now you actually have 250,000 harvesters concentrating in six or seven swing states. It doesn’t take many ballots per harvester to swing them the count.
Of course, these were the emergency ballots held back in case needed. At around midnight, when Trump was way ahead from voters who knew what they were doing, they called HALT to truck in the harvested ballots - many not even folded - and turn the election to Boden.