More than 70 million Americans have cast ballots in the US presidential election, over half the total turnout of the 2016 election, according to a new tally.
With one week to go until Election Day on November 3, Americans have sent in ballots in record numbers, driven by the impact of the coronavirus on voting.
According to a tally by the US Elections Project, the election could lead to the highest voter turnout in percentage terms in more than a century, is the latest sign of intense interest in the contest between Republican President Donald Trump and Democratic challenger Joe Biden.
Democrats hold a significant advantage in early voting due to their embrace of mail balloting, which Republicans have historically cast in large numbers but have shunned amid repeated and unfounded attacks by Mr Trump, who says the system is prone to widespread fraud.
Overall, Democrats hold roughly a two-to-one advantage in early voting numbers.
However, Republicans in recent weeks have narrowed the gap in early, in-person voting, data shows.
The high level of early voting has led Michael McDonald, the University of Florida professor who administers the US Elections Project, to predict a record voter turnout of about 150 million, representing 65 per cent of those eligible to vote, the highest rate since 1908.
US voters have already cast far more early votes during this presidential campaign than they did in all of 2016 when they passed the 47 million mark earlier this month, data shows.
Mr Trump questioned the integrity of the election again on Tuesday, saying it would be "inappropriate" to take extra time to count the tens of millions of ballots cast by mail.
While Mr Trump, who trails in national opinion polls, cast doubt on mail-in votes, Mr Biden offered a message of unity in two rallies in the state of Georgia as part of a foray into traditional Republican territory.
The huge volume of mail ballots 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.
"It would be very, very proper and very nice if a winner were declared on November 3, instead of counting ballots for two weeks, which is totally inappropriate and I don't believe that that's by our laws," Mr Trump told reporters at the White House before leaving for campaign rallies in three states. "We'll see what happens."
Mr Trump has repeatedly and without evidence suggested that an increase in mail voting will lead to an increase in fraud, although election experts say that is rare in US elections.
Mail voting is a long-standing feature of American elections, and about one in four ballots was cast that way in 2016.
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.
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