It’s Election Day. But around 100 million Americans already voted early.

• Tuesday November 3 is Election Day in the US. Around 100 million people voted in advance, more than doubling previous record in 2016.
• More than 35 million early in-person votes have been cast, and almost 64 million mail-in ballots have been returned, according to the US Elections Project.
• This means voters have already cast 72.3% of the total votes counted in the 2016 general election.
• The surge of early voting — driven by the COVID-19 pandemic — means that the votes cast on Election Day will likely be a smaller proportion of the total than ever before.
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Polls are opening across the US today for Election Day. But around 100 million Americans had already voted, an unprecedented shift that is projected to be part of a record voter turnout.

This year’s early voters represent a huge increase from 2016. In that contest almost 139 million people voted, with a around a third of the votes cast ahead of Election Day.

Some 99.7 million votes had been cast as of 1. a.m. ET on Tuesday, according to the US Elections Project. Those early votes are equal to 72.3% of the total votes counted in the 2016 general election.

This is made up of more than 35 million early in-person votes, and almost 64 million returned mail-in ballots.

Another 28 million mail-in ballots are still outstanding.

The number of ballots already cast likely means that today's voters will form a smaller group than those who have already cast their vote.

Early-voting queues lasted hours in some states, with many early voters motivated by the coronavirus pandemic.

And millions of people sent their votes by mail — which could become a source of contention as President Donald Trump has repeatedly sought to cast the process as one that's vulnerable to fraud, despite large amounts of evidence to the contrary.

Trump has made clear that he intends to contest the validity of many ballots, particularly mailed ones, seeking to disqualify them.

The first polls to open in the country were in parts of Vermont, at 5 a.m. Pre-dawn voters were pictured lining up in Virginia and Kentucky too.

The large number of mail-in ballots mean that it is unlikely to be clear which candidate won in many states on election night. In some, it could take days for a victor to be declared.

Business Insider reporters Eliza Relman and Oma Seddiq have put together a guide for what to watch on election night and the days following as results start to come in.

Polls show a Biden lead

The most recent polling shows Democratic challenger Biden with around a 10 percentage point lead over Trump in an average of national polls.

But with counts in key states expected to take days and Trump allies preparing to dispute ballots, a clear final result could take some time.