An estimated four million Americans have already cast their ballots, less than a month to the 3 November election.
The number is 50 times the 75,000 that had voted at this time in 2016, according to the United States Elections Project, which compiles early voting data.
The unprecedented pace of early voting numbers, USEP believes, indicates a possible record turnout for the showdown between President Donald Trump and Democratic challenger Joe Biden.
The shift has been driven by an expansion of early and mail-in voting in many states as a safe way to cast a ballot during the coronavirus pandemic and an eagerness to weigh in on the political future of Trump, said Michael McDonald of the University of Florida, who administers the project.
“We’ve never seen this many people voting so far ahead of an election,” McDonald said.
“People cast their ballots when they make up their minds, and we know that many people made up their minds long ago and already have a judgment about Trump.”
The early surge has led McDonald to predict a record turnout of about 150 million, representing 65% of eligible voters, the highest rate since 1908.
Biden leads Trump in national opinion polls, although surveys in crucial battleground states indicate a tighter race.
The numbers reported so far come from 31 states, McDonald said, and will grow rapidly as more states begin early in-person voting and report absentee mail-in totals in the next few weeks.
All but about a half-dozen states allow some level of early in-person voting.
The percentage of voters who cast their ballot at a voting machine on Election Day already had been in steady decline before this year, according to the U.S. Election Assistance Commission, a federal agency.
The total number of early or mail-in votes more than doubled from nearly 25 million in 2004 to 57 million in 2016, it said, representing an increase from one in five of all ballots cast to two in five of all ballots cast.