John C. Fortier and Charles Stewart III have an AEI report titled Lessons learned from the 2020 election.
The 2020 election witnessed a continuation oftrends established in recent elections, whereby vote counting has slowed and the votes counted are disproportionately Democratic the further away from Election Day the counting proceeds. These trends are due to certain types of ballots taking longer to count completely and large urban areas taking longer to complete the vote count. » Despite these national generalities, many states deviated from the national trend. » In 2020, most states counted nearly 100% of their final totals of ballots within 48 hours of polls closing on Election Day. Six states — Iowa, Florida, North Carolina, Oklahoma, Tennessee, and Louisiana — counted nearly one hundred percent of their total ballots within four hours of polls closing. » Research that has looked at the speed with which states reported their votes has concluded that (1) states with more mail ballots are slower to report vote totals, (2) states that limit the pre-processing of mail ballots are slower, and (3) states that allow mail ballots to arrive after Election Day are slower. » The magnitude of the “blue shift,” the pattern whereby later-counted ballots are disproportionately Democratic, depends on when one starts the 4 comparison. Indeed, if one compares final election results with vote reports in the first three hours following polls closing, there was a national “red shift” in 2020. » Many states have certification deadlines that come very close to the “safe harbor” benchmark for certifying elections, thus perhaps giving insufficient time for careful consideration of recounts and challenges.