The 2020 presidential campaign has been unlike any other as a raging coronavirus pandemic that has so far caused more than 225,000 U.S. deaths pushes record early voting. More than 69.4 million votes have been cast so far, approaching half the total 2016 votes.
Early voting, both by mail and in person, has surged to record highs as Americans have rushed to cast ballots in the election while looking to avoid exposure to the coronavirus.
Trump cast an early ballot in Florida's West Palm Beach on Saturday.
Mail voting is a long-standing feature of American elections, and about one in four ballots was cast that way in the 2016 election.
The huge volume of mail ballots – more than 46 million have already been cast – could take days or weeks to tally, experts say, meaning that a winner might not be declared the night of November 3, when polls close.
U.S. President Donald Trump questioned the integrity of the U.S. election in his race against Democrat Joe Biden again on Tuesday, saying it would be "inappropriate" to take extra time to count the tens of millions of ballots cast by mail.
Democratic officials, activists and voters have voiced deep anxieties that Trump will not accept the outcome if he loses. Biden has called it his biggest fear.
Democrats are voting early in greater numbers than Republicans this year, according to data from the U.S. Elections Project at the University of Florida.
The race is tighter in battleground states including North Carolina, Florida and Arizona where the election might be decided. A Reuters/Ipsos poll on Tuesday showed Biden with a 52 percent - 43 percent lead over Trump in Michigan, with the two statistically tied in North Carolina.
While Republican Trump, who trails in national opinion polls, cast doubt on mail-in votes, Biden offered a message of unity in two rallies in the state of Georgia as part of a foray into traditional Republican territory with a week left to go before Election Day on November 3.
Biden's visit to Georgia was a show of optimism that his campaign can end the presidency of Trump. Georgia has not supported a Democrat in a U.S. presidential election since 1992.
"I'm running as a proud Democrat, but I will govern as an American president. I'll work with Democrats and Republicans," Biden said in Warm Springs.