What role did mail-in and early voting play in Joe Biden's vote count in 2020?
Executive summary
Mail-in and early voting played a decisive operational role in shaping when and how Joe Biden’s 2020 votes were counted and reported: a record share of Americans voted before Election Day or by mail, producing counting delays and a “blue shift” in several swing states as absentee ballots were tallied after in-person votes, and those patterns materially contributed to Biden’s late gains in counts reported after Election Night [1] [2] [3].
1. A record surge in mail and early ballots changed the tempo of results
The 2020 election was the first modern presidential contest in which a plurality of voters cast ballots by mail and a majority voted before Election Day, creating an unprecedented backlog of absentee and early ballots that simply were not captured on Election Night and therefore altered the chronology of reported results [1] [3]; election officials and newsrooms warned that early returns would undercount mailed votes and that final tallies would continue for days [2] [3].
2. Counting rules and timing produced the “blue shift” in key states
Procedural differences — notably laws or administrative practices that prevented some states from processing or counting mail ballots before polls closed — meant many absentee ballots were counted later and, in several battlegrounds, tended to favor Biden, producing visible shifts toward him as those ballots were added to totals [1] [2]. By contrast, jurisdictions that allowed earlier processing sometimes reported more of the mail vote sooner, producing different-looking Election Night trajectories [1].
3. Partisan behavior and campaign messaging influenced the partisan mix of late ballots
Trump repeatedly discouraged mail voting while Democrats generally promoted mail and early voting as safer amid the pandemic, and as a result more Democrats used mail ballots in 2020; multiple outlets and analyses described a pattern in which many absentee/mail ballots leaned Democratic and in-person Election Day turnout that night leaned more Republican, contributing to late shifts where states’ counted mail ballots favored Biden [1] [4].
4. The effect on Biden’s final totals was real but procedural, not evidence of widespread fraud
The late counting of mail and early ballots materially affected the timing of Biden’s gains — in several states those ballots closed margins enough to secure his certified wins — and courts rejected major legal challenges to mailed-ballot practices in places like Pennsylvania and Michigan, with judges calling many claims “incorrect and not credible,” which addresses legality and credibility though not the partisan implications of ballot timing [5]. Independent research cited across the reporting also indicates that while mail voting changed when votes were cast and counted, large-scale fraud claims lack substantiation in mainstream analyses [6] [5].
5. Data limitations and contested narratives: what reporting does and doesn’t show
Some partisan sources later claimed tens of millions of “unaccounted for” mail ballots or localized large discrepancies, but those reports come from groups or outlets whose methodologies and conclusions have been disputed, and mainstream coverage emphasized that counting procedures, postmark rules and the unprecedented scale of mail voting better explain the late swings than allegations of systematic ballot disappearance [7] [1] [8]. Reporting also shows evolving postal and postmark policies can affect late-arriving ballots — an issue underscored in later postal policy debates — but the direct attribution of lost or fraudulent ballots to Biden’s margin is not established in the cited mainstream sources [8] [9] [10].
6. The broader lesson: timing, access and communication, not a single causal gimmick
The dominant, evidence-based reading across the reporting is that mail-in and early voting altered both the mechanics and public perception of 2020’s count — accelerating turnout among voters who preferred or needed to vote early and delaying final results because many of those votes were tallied later — and that this combination helped produce Biden’s late reported gains without changing the fundamental legitimacy of the count as upheld by courts and post-election audits [1] [2] [5]. Election officials and media outlets have since focused on clearer communication about when different ballot types will be counted to avoid the same confusion in subsequent cycles [4].