1. Halt counting (or at least 'reporting') in critical swing states simultaneously. We all saw this happen.
2. Kick out poll watchers
3. Figure out how many votes your preferred candidate needs.
4. Examine the voter rolls and see who never turned in a ballot.
5. Fill in ballots for those people (and if you're in a rush, don't even bother to vote in any down-ballot races) and mix them in with the legitimate ballots.
If you control a few key urban centers in a few key states - you can definitely pull this off. Given the behavior of the left over the last 4 years, I absolutely believe they did something like the above.
> Given what my extremely biased sources have told me about the behavior of the left over the last 4 years
FTFY
> Kick out poll watchers
Were any poll watchers kicked out? Trump's claim that there weren't poll watchers in Pennsylvania all turned out to be false; their lawyer admitted in court that they actually had 19 observers in the room [1].
EDIT Meanwhile, the graphs in TFA shows that there are "bumps" in the curve, showing that Democratic-leaning counties had lower turnout in the 2016 election. This is consistent with the widespread reports of Republicans trying to suppress the vote in Democratic-leaning areas, of which [2] and [3] are more recent examples.
2. Kick out poll watchers
3. Figure out how many votes your preferred candidate needs.
4. Examine the voter rolls and see who never turned in a ballot.
5. Fill in ballots for those people (and if you're in a rush, don't even bother to vote in any down-ballot races) and mix them in with the legitimate ballots.
If you control a few key urban centers in a few key states - you can definitely pull this off. Given the behavior of the left over the last 4 years, I absolutely believe they did something like the above.