An early morning surge of Biden votes erases Trump’s lead.
Below is a chart (from FiveThirtyEight) showing Trump leading in Wisconsin throughout election night November 3–4.
Then, at around 4am, a surge of Biden votes suddenly appears, closing the gap with Trump.

Maybe there’s a valid explanation for this increase — a common response on social media has been that Milwaukee absentee ballots were factored in.
But that leaves another question: How did the same thing happened in Michigan, at around the same time?