Image source, EPA

Nearly 30 million people cast their ballots before the official election day in 2020.

Early voting - which allows people to vote in-person or by mail before election day - has previously favoured the Democratic Party. Their candidate, Joe Biden, won the presidential election in 2020.

Historically, Democratic voters have tended to participate in mail-in voting in higher rates, also known as casting an absentee ballot. In the 2024 election, Republicans are trying to encourage more early-voting/mail-in voting.

Republicans have previously heavily criticised mail-in voting as being ripe with fraud. Numerous national and state-level studies have shown that although there have been isolated cases, electoral fraud is very rare.

Many US states have begun early voting in the 2024 presidential election - and it's off to a rapid start.

More than 300,000 ballots were cast on the first day of early voting in the key battleground state of Georgia.

Harris has had a small lead over Trump in the national polling averages since she entered the race at the end of July and she remains ahead - as shown in the chart below with the latest figures rounded to the nearest whole number.

Harris saw a bounce in her polling numbers in the first few weeks of her campaign, building a lead of nearly four percentage points towards the end of August.

But the numbers have been relatively stable since early September, even after the only debate between the two candidates on 10 September, which was watched by nearly 70 million people.

You can see how little the race has changed nationally in the last few weeks in the poll tracker chart below, with the trend lines showing the averages and the dots showing the individual poll results for each candidate.

While these national polls are a useful guide as to how popular a candidate is across the country as a whole, they're not necessarily an accurate way to predict the result of the election. That's because there are seven swing states that are likely to decide the whole race.

Right now the polls are very tight in the seven states considered battlegrounds in this election and neither candidate has a decisive lead in any of them, according to the polling averages.

You can read more about where the polls stand here.

Caitlin Wilson
US live editor

Good morning from Washington DC, where we are restarting our live coverage of the US election campaign.

With just a little more than two weeks to go until election day, Donald Trump's and Kamala Harris's travels around the country - trying to convince Americans to trust each of them to be the next president - are ramping up to an all-out sprint.

We're expecting to see the candidates in at least four of the seven major swing states on Saturday alone - not to mention their running mates and other campaign allies who are also out on the trail.

Harris is headed to Michigan and Georgia, where she's set to appear with music stars Lizzo and Usher. Trump is expected in Pennsylvania and North Carolina, which is still reeling from damage caused by Hurricane Helene.

We'll bring you the top lines from those rallies throughout the day, so be sure to check back for the latest.

Meanwhile, residents in about half of the 50 states have already begun casting their ballots in early voting. On Saturday, polling stations open in Massachusetts and key swing state Nevada - we'll check in to see how it's going a little later.

And we'll be keeping an eye out for any reactions to the news of the last few days, including a judge unsealing nearly 1,900 pages of documents in the criminal case against Trump over his alleged actions following the 2020 election.

Stay with us - it's another big day and we'll keep you up to date with it all.

Brandon Livesay
Reporting from New York

There's a lot of noise in this US election, but on Friday night it was the absence of audio that stood out.

At Donald Trump's rally in Detroit, his microphone stopped working about 10 minutes into his speech. He stalked around the stage for more than 15 minutes, waiting for it to work again.

It was somewhat reminiscent of Trump's town hall earlier this week when he stopped answering questions and swayed onstage for 39 minutes while listening to his favourite songs with the crowd.

Trump did have a working mic earlier today, where he said Kamala Harris doesn't have the energy of a rabbit. That was in response to Harris suggesting Trump was too exhausted to campaign.

The two rivals are ramping up their political jabs at each other, and today's topic of choice was stamina. If either candidate is struggling with the pace of this frenetic campaign, they'll have a tough 18 days ahead of them.

We're pausing our live coverage for Friday, but will back again tomorrow to bring you the latest updates.

In the meantime, here's some of our latest US politics coverage which is well worth a read:

• Our quick guide to the swing state of Michigan, where both Harris and Trump campaigned today
• Ten US states will have abortion questions on the ballot in November
• Trump and Harris roast each other for charity event - here are four gags

Thanks for following along.

Both Kamala Harris and Donald Trump have finished their respective rallies, which were both held in the battleground state of Michigan.

Here's what you may have missed on the campaign trail on Friday, with just 18 days left until the election.

• Trump and Harris exchanged insults about who has more stamina, with Harris saying Trump was suffering from "exhaustion" and Trump calling her a "loser" with low energy
• Both presidential candidates focused on Michigan today, attempting to win over the midwestern state's autoworkers and significant Arab and Muslim minority
• Their visits to Michigan came after the judge overseeing Trump's federal election interference case released evidence about his alleged attempts to overturn his 2020 loss, which culminated in the 6 January riot at the US Capitol
• Polls are indicating an extremely tight race between the two candidates, with barely more than two weeks to go until vote counting begins

Image source, Getty Images

More now from the Kamala Harris rally, where she has thanked members of the Arab-American community who are in attendance.

She is aiming to win over the state's large Arab and Muslim population, after members of that community voiced their anger at Harris and Biden over Israel's war in Gaza.

"Listen, I know given the scale and death and destruction in Gaza, and given the civilian casualties and displacement in Lebanon, it's devastating."

"And now, with Sinwar's death, everyone must seize this opportunity to finally end the war in Gaza," she says, referring to Israel's killing of Hamas's leader in Gaza.

She pledges that as president she will "do everything in my power to achieve these goals" for "future with security and dignity for all people in the region".

Let's pivot from Trump's rally in Michigan to check in on Kamala Harris. The vice-president is holding her own rally in Oakland County, Michigan.

And she's had to pause mid-speech also. A medic is needed in the crowd.

"We got a lot of folks in here. It's a little warm, let's just making sure we're watching out for each other," she says.

Prior to the pause, the crowd sang Harris Happy Birthday. She will turn 60 on Sunday.

Brandon Livesay
Live editor

Donald Trump has audio once again, after an incredibly bizarre 15 minutes where he was forced to walk about the stage and stare at the crowd while waiting for his microphone to work again.

"I won't pay the bill," he immediately says.

"If it goes off again I'll sue the ass off that company," he adds, with the crowd cheering loudly.

And with that, as if the strange stretch of time we just witnessed never happened, he's back into his usual talking points.

Image source, Reuters

Donald Trump is now back behind his podium, looking around at the crowd with a stern expression on his face

Apparently there are audio issues at the Michigan rally, and his microphone stopped working mid-speech.

He's been walking around the stage for about 11 minutes now as the crowd chants various phrases.

Donald Trump has stopped speaking and is currently pacing back and forth on the stage.

This has been happening for several minutes now.

The crowd is cheering loudly and chanting various phrases, but we don't know the reason for this delay.

Stick with us.

Donald Trump is now speaking at a rally in Detroit, Michigan.

"We love Detroit," he starts off by saying. "We win Michigan, we win the whole ball game," he tells the crowd.

Trump had made a jab at the city just over a week ago, when he said the whole country would end up like Detroit if Kamala Harris is elected.

But tonight he has so far been full of praise for the city, saying he will rebuild its auto industry.

Detroit, the largest city in Michigan, is the heart of the automotive industry in the US - making the issue top of mind for voters in the surrounding areas.

Read more: A quick guide to swing state Michigan

Image source, Getty Images

Happening at the same time as Donald Trump's rally in Detroit (where Trump is yet to appear), is a rally in Tucson, Arizona with former President Barack Obama.

Obama is spending much of his speech talking about Trump.

"What I cannot understand is why anyone would think that Donald Trump would shake things up in a way that is good for you. Because there is absolutely no evidence that this man thinks about anybody but himself," Obama says.

"When he's not complaining, he's trying to sell you stuff," he says about Trump. He brings up Trump selling Bibles which are made in China.

The partisan crowd is clearly energised by Obama's appearance, and his frequent jabs against Trump.

Lisa Lambert
Reporting from Washington DC

While we wait for Donald Trump to appear at his rally in Michigan, let's take a moment to look at some of the evidence that was unsealed today in the former president's 2020 election fraud case.

Hundreds of pages shared by special counsel Jack Smith today simply have the word "Sealed" stamped across the top and nothing else.

The unsealed portions don't appear to have any bombshells. Instead, they follow certain themes that show us how Smith is working within the limits set by the Supreme Court.

The Supreme Court ruled that "the President has no authority over state legislatures or their leadership" and that he was not immune from prosecution when it came to dealing with state legislatures.

A lot of the unsealed evidence involves state lawmakers and officials describing interactions with Trump and the campaign, especially when it comes to allegations of voter fraud.

There are also many sections on conversations inside the White House on election night 2020 about declaring victory. It may have been included to paint the picture of Trump as a political candidate versus a president giving an official address.

Both Vice-President Kamala Harris and former President Donald Trump are campaigning in the swing state of Michigan today.

Harris is set to speak at campaign events in Lansing and Oakland County, while Trump will hold a rally in Detroit shortly.

Stay with us for updates.

Caitriona Perry
Reporting from Tucson, Arizona

Image source, Caitriona Perry / BBC

Emily Edwards - a mother of three young children - says economic issues are really important for her in this election. Her husband is on active duty with the US military, and while she does a little part-time work when she can, they are effectively a single-income family.

“We’ve seen the cost of living rise steadily over the last four years. The last time our budget was this tight was 2008”, she says.

She’s also concerned about abortion rights becoming too liberal in the state of Arizona. Voters there will vote on a proposal to enshrine the right to an abortion into the state’s constitution, extending the limit from 15 weeks, up to the moment of viability, generally considered to be between 22 and 24 weeks of pregnancy.

“For me and my family,” she says, “that just goes too far”.

Immigration is also of concern to her. She grew up in Southern California and has lived near the border with Mexico for most of her life, but she sees a rise in homelessness and drug abuse in Tucson as directly related to what she feels is an unsecure border.

She has voted for Donald Trump in 2016 and 2020 and tells me she will be voting for him again. “I’m actually a registered Democrat but I will be voting for Donald Trump”. Emily says that she may vote for some Democrats in some of the down ballot races, for other elected office, but she will not be voting for Kamala Harris.

Trump has been taking questions from supporters at his roundtable in Detroit with the help of congressman Byron Donalds, a prominent Republican from Florida.

The questions have mostly been full of praise for Trump and his policies.

One man, whose office was destroyed and loved ones killed at the World Trade Center on 11 September 2001, said he supported Trump because he understood the need "to crush jihad from the Earth".

A woman from Dearborn, Michigan, praised him for being endorsed by RFK Jr, a critic of vaccines who ended his own presidential campaign to support Trump. She voiced concerns about modern healthcare, saying that it was a threat to public health.

Trump praised her and said he would try to arrange a meeting between her and RFK Jr.

Another man told Trump that he feels inspired when he sees Trump's praise of the police and military. Echoing Trump's comments about political opponents, the man tells him he agrees that "the enemy has got us surrounded".

• For context: Trump's visit to Detroit comes after he likened the city to a "developing nation" and called it horrible last week. He went further again on Tuesday, telling the Economic Club of Chicago: "It's just horrible because we've been talking about Detroit's coming back for 40 years, and it's never come back."

Caitriona Perry
Reporting from Tucson, Arizona

Adriana Girjava is a student at the University of Arizona in Tucson. There are about 44,000 students on campus.

She has been through two shootings on campus. The first was about two years ago when a professor was shot and killed, and the other just a few weeks ago when rival gangs opened fire on one of the campus playing fields.

“For me, it’s about gun safety,” she says about the election. “It was scary. Students are scared. We want to feel safe”.

She says she’s made up her mind: “It’s Harris-Walz. No question.”

As a young woman, Adriana says she is also concerned about abortion rights and wants a president who will protect them rather than put them at risk.

She’s also encouraging fellow student to vote. She thinks young people are turned off by politicians and politics, and she spends her spare time working to increase their engagement and to advocate for gun safety.

All over campus there are signs encouraging students to vote.

Joe Biden won Arizona in 2020 by just 10,457 votes. The signs note that there are 384,858 students in the state of Arizona and they need to make their voices heard, for whichever candidate they choose.

Caitriona Perry
Reporting from Tucson, Arizona

Image source, Caitriona Perry / BBC

Tucson, Arizona is nestled in the middle of the Sonoran desert, bordered by the beautiful Catalina mountains. Cactus dot the landscape and the scorched, brown red earth is the landscape used in many Western movies.

Today, a show of a different kind rolls in to town. Former US President Barack Obama will hold a rally here in support of Vice-President Kamala Harris.

Arizona is one of the key battleground states. Both Harris and former President Trump have been to the state in the last week, as have their running mates Governor Tim Walz and Senator JD Vance.

The race is tight in Arizona. Just a few percentage points separate the candidates in most polls, and generally any lead is within the margin of error.

According to statistics from the Arizona Secretary of State, there are more registered Republicans than Democrats in the state, but 29% of voters are registered independent and so the candidates are trying to sway them.

Tucson is home to the University of Arizona, and has 44,000 students on campus, and Obama is targeting their votes, among others.

Trump has now responded after Harris earlier today accused him of cancelling media interviews because of "exhaustion".

"I've gone 48 days now without a rest," he says, calling Harris "a loser who doesn't have the energy of a rabbit".

Watch what they both said in the video above.