The 20.8 million ballots submitted as of Friday afternoon represents 15 per cent of all the votes cast in the 2016 presidential election, even as eight states are not yet reporting their totals and voters still have more than two weeks to cast ballots.
Americans' rush to vote is leading election experts to predict that a record 150 million votes may be cast and turnout rates could be higher than in any presidential election since 1908.
Republicans have been bracing themselves for this early Democratic advantage for months, as they've watched President Donald Trump rail against mail-in ballots and raise unfounded worries about fraud.
Polling, and now early voting, suggest the rhetoric has turned his party's rank and file away from a method of voting that, traditionally, they dominated in the weeks before election day.
That's why, despite Trump's rhetoric, his campaign and party are encouraging their own voters to cast ballots by mail or early and in-person.
"This is all encouraging, but three weeks is a lifetime," Democratic data strategist Tom Bonier said of the early vote numbers.
Republicans argue that these signs of enthusiasm are meaningless — Democratic early voters are people who would have voted anyway, they say.
But an AP analysis of the early vote shows eight per cent of early voters had never cast a ballot before, and 13.8 per cent had voted in half or fewer of previous elections for which they were eligible.
Of the early voters, 82 per cent cast ballots through the mail and 18 per cent in person.
Black voters cast 10 per cent of the ballots cast, about the same as their share of the national electorate, according to the AP analysis of data from L2, a political data firm.
Traditionally, younger and minority voters send their mail ballots in closer to election day or vote in person.
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