1) record-smashing demand for mail ballots
2) unprecedented polarization of mail (D) vs. Election Day (R) votes
3) overwhelmed & understaffed election offices
4) absentee voter inexperience/error
5) counting delays/legal chaos
But the race could still tighten. And in the past 20 years...
7 Electoral College
12 Senate
71 House
...races have been decided by <2%.