Most polls have closed on a busy first day of early voting in Florida, and our live page will do the same. With just two weeks left until the 3 November 2020 US presidential election, candidates are scrambling to deliver their final pitches to voters - and are making plenty of news on the campaign trail as they do.

Here are some of the key events from Monday:

• The first day of early voting in Florida, a crucial battleground state, saw long queues that promise a hard-fought election to come
• Kamala Harris, the Democratic vice-presidential candidate, made campaign stops in the state as her running mate, Joe Biden, prepared for Thursday night's presidential debate away from the spotlight
• President Trump attacked Dr Anthony Fauci, the top US infectious disease expert, before hitting the trail in Arizona, another battleground state
• The political tussle over public health and the economy that has been central to the campaign continues, as more states begin early voting later this week

We'll be back tomorrow with the latest campaign news and analysis. Monday's live page was brought to you by Matthew Davis, Boer Deng, Sophie Williams, Max Matza, Ritu Prasad and Holly Honderich.

Their man may be behind in the national polls, but Republicans see hope in rising voter registrations in three key states that could yet yield the re-election of President Trump come November.

Though registered Democrats still outnumber registered Republicans in Florida, Pennsylvania and North Carolina, data has shown that the gap has narrowed since 2016.

The Democratic advantage in Florida and Pennsylvania has shrunk by about 200,000 voters and in North Carolina by more than 230,000 voters.

US presidential elections are not won by overall popularity but by having the right number of votes in the right places. Trump won all three states in 2016 in part because voters turned out for him and not for his rival. If registration is a measure of enthusiasm, Republicans may yet have reason to believe voters will turn out for Trump again.

Image source, Getty Images

For this history-making election, Americans are going to the polls in the midst of the coronavirus outbreak.

The pandemic's impact on the economy has hit young people disproportionately hard - a strain that is expected to leave a mark on their politics, possibly widening the gap with older, more conservative Americans.

Research has found that people hit by economic downturns during their formative years are more likely to favour redistributive policies and attribute success to luck rather than hard work - and that will influence how they vote.

Read the stories of the young Americans struggling in the 2020 economy.

Holly Honderich
BBC News, Washington DC

Democratic candidate Joe Biden seems to have cornered at least one constituency - celebrities.

Taylor Swift, Madonna, Cardi B, Tom Hanks and George Clooney have all thrown their support behind the Democratic ticket.

In an editorial for V magazine, Taylor Swift urged fans to vote for Mr Biden and Ms Harris, and promptly shared the endorsement with her 140 million Instagram followers.

And Dwayne Johnson - a self-described independent and now the most-followed American man on Instagram - made his first-ever endorsement, saying in a video that Joe Biden and Kamala Harris are "the best choice to lead our country".

This summer's Democratic National Convention, too, featured a parade of Oscar winners, musicians and professional athletes - an apparent contrast to the Republican convention the following week. There, the president himself was the biggest celebrity in attendance.

But does all this matter? Read the full story here.

While on the campaign trail this morning, Trump spoke to reporters about his recent brush with Covid-19, which landed the president in hospital for several days at the beginning of the month.

Asked whether he would authorise his doctors to release information on when his most recent negative test was, he had this to say:

Postal votes! Swing states! The Electoral College!

There sure is alot of jargon associated with US elections - and details of how things work that even many American voters are unclear about.

If you need a refresher, here's our really simple guide.

Image source, Getty Images

Democratic vice-presidential candidate Kamala Harris turned up at the University of North Florida in Jacksonville this afternoon to kick off early voting in the state, which began today.

"The voters of Florida, you guys are going to determine the outcome of this election," the California senator said. "You [all] are going to have an impact on people you'll never meet"

Harris brought out familiar lines of attack against President Trump - saying he failed to act even when he knew of the severity of the coronavirus outbreak - and touted her running mate, who is preparing for Thursday night's debate, leaving the campaigning up to her.

"This is the difference between a Donald Trump and Joe Biden," she said. "We know that the strength of our democracy is the strength within our people."

Harris has returned to the campaign trail following a brief pause after two aides tested positive for coronavirus last week.

Ritu Prasad
BBC News writer

The US Supreme Court is in the spotlight for voters this year for many reasons. One of the top issues is healthcare.

On 10 November, the court will consider a case on a popular Obama-era public healthcare law, the Affordable Care Act.

Out of the 23 million Americans who are currently insured by the ACA or Medicaid, another public health option, 21 million could lose their insurance if the law is overturned.

Down the road, more could drop their plans if a lack of federal subsidies sends insurance prices sky-high.

As one young voter told me: "They can debate and turn this into a political issue all they want, but it's not political when you see your mom in a hospital bed."

And the backdrop to all this - a global pandemic that's affected more than 7.5 million Americans.

Read the stories of four US patients whose lives could change if the ACA is overturned here.

Image source, Getty Images

Congresswoman Alexandria Ocasio-Cortez is doing some gaming to get out the vote.

The lawmaker has asked her Twitter followers if they wanted to join her for an online session of Among Us - a murder mystery style game - on Twitch, the video games-streaming platform.

The digital invite from 'AOC', a 31-year-old millennial, is among a growing number of attempts to reach young voters on social platforms. Instagram has been flooded in recent days with celebrities posting their "I Voted" selfies, and stars of TikTok - which launched an in-app voting guide - are also making their political inclinations known.

It remains to be seen whether these new get out the vote strategies will work. Young people have a historically bad track record for turning out on election day.

Image source, Getty Images

If Joe Biden and Donald Trump agree on anything, it's that this year's election is an important one. It's also happening under unprecedented circumstances. Americans will cast their ballots as the country struggles against the coronavirus outbreak. As a result, more Americans are voting by post than ever before.

An estimated 80 million ballots will be cast by mail this year as states aim to prevent gatherings to limit the spread of coronavirus.

That means delays.

Postal ballots need extra time to be delivered, and they also take longer to count once they have arrived. So though we'll see votes returned on election day - 3 November - don't expect final results until days after.

Read more about what a delayed result could look like.

With the coronavirus pandemic, the political theatre looks a little different this year. At rallies for Joe Biden and Kamala Harris, supporters maintain a social distance, and drive through in their cars.

And at Trump events, where masks are less common, supporters undergo temperature checks before entry.

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images

A government watchdog will investigate alleged "political interference" from the White House at the Centers for Disease Control and Food and Drug Administration (FDA), at the behest of several Democratic lawmakers.

The Government Accountability Office (GAO) said on Monday it would look into whether the administration "violated the agencies' scientific integrity and communication policies". The inquiry was requested by Senators Elizabeth Warren, Patty Murray and Gary Peters.

There have been reports of administration officials trying to pressure the agencies into changing guidance to match the president's assessment that the US has beaten Covid-19.

Trump has often dismissed health officials (most recently Dr Fauci) and their recommendations as overly cautious. He insisted that the FDA authorise the drug hydroxychloroquine to treat Covid-19, despite divided evidence on efficacy.

The GAO is an independent agency that takes on such inquiries for Congress.

Image source, Getty Images

More than 245 million Americans are eligible to vote this year, But only a small percentage of them will actually determine who the next president is. So who are they and where do they live?

After criticising the country's top infectious disease expert Dr Anthony Fauci this morning, President Trump doubled down on the denunciation at a campaign rally this afternoon in Arizona.

The president then turned to his rival, Joe Biden, saying that the Democrat "wants to listen to Dr Fauci".

Fauci has served as the National Institute of Allergy and Infectious Diseases since 1984, and has become one of the most visible figures in the government’s coronavirus response.

But Biden doesn't seem to mind the association with Dr Fauci. He retweeted the president's remarks with a simple "yes".

Fauci has served under six US presidents - both Democrats and Republicans - and he knows a bit about the rough and tumble politics of Washington.

Over his five decades as a medical researcher, he has seen his effigy burnt, heard the cries of protesters calling him a "murderer", and had smoke bombs thrown outside his office window.

You can read our profile here.

Image source, Getty Images

First Lady Melania Trump is expected to join her husband at a campaign rally in Pennsylvania on Tuesday night.

It's not rare for a political spouse to make campaign stops, but it is rare for Melania - this will mark her first in-person campaign appearance in more than a year, aside from the Republican National Convention in August. She was also ill with Covid-19 earlier this month.

As far as campaign events go, she'll have some stiff competition. Also tomorrow, the Democratic vice-presidential pick Kamala Harris will be joined by some Marvel superheroes. The California Senator will be flanked by some of the actors who play members of the Avengers squad: Chris Evans, Don Cheadle, Scarlett Johansson, Paul Rudd, Mark Ruffalo and Zoe Saldana.

Image source, Getty Images

Today is the first day of early voting in Florida, a crucial swing state, and those turning up are trending younger, according to preliminary data from liberal analyst group Catalist. Of course, especially in Florida, which is known for its elderly population, younger means under-65.

So far, the under-65s account for around half of the cast ballots - a 12 point rise from 2016, CNN reports.

As early voting kicked off today, some 2.5m residents of the Sunshine State had already sent in their votes by mail. According to the Tampa Bay Times, that's close to the total number cast in the 2018 midterm election.

During the August primary elections, Floridians overwhelmingly opted to vote by mail. But so far, there's been a lot of enthusiasm at the polls.

Check out a timelapse below, captured by a CBS News reporter in Miami earlier this morning, of voter lines at the public library despite the soggy morning.

With just over two weeks left until election day - and a record 29m votes already cast nationwide, the candidates are scrambling to make their last pitches to voters across the country.

Who is ahead in the polls - and does it matter?

Here, we break down all the most recent key data.

Abdul “Rab” Razzak is a palliative care specialist born in Bangladesh and raised in New Jersey. He enthusiastically supports Joe Biden.

"Biden and Harris have shown they will listen and allow experts to speak freely about the reality of Covid-19 and climate change, as well as other issues. They show integrity and humility. They demonstrate what true servant leadership is - helping lift people that they serve."

Rab is a member of our US election voter panel. You'll hear more from him, and many of our other voters, throughout the week.

Join the conversation:

• We want to hear from you - what questions do you have about the US election?
• In five words, tell us what's at stake in this election.

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President Donald Trump is in Prescott, Arizona, for the first of two rallies in the state today. Trump won Arizona in 2016, but is trailing behind his rival Joe Biden in recent polls.

"How can you be three points up when we have crowds like this?" Trump says, addressing Biden's poll lead.

Attacking his rival, Trump tells supporters they have "a choice between the American dream and a socialist nightmare".

Biden, he says, will "massively" raise taxes, and impose costly regulation. At points, the crowd responds with chants of "lock him up!".

Trump also laments his loss in support from suburban women.

"I like women, I like women," he says.

Image source, Reuters

Joe Biden’s campaign has accused Trump of “reckless and negligent leadership ”following his attacks on scientists and medical experts in recent days.

In a campaign conference call on Monday, Trump branded Dr Anthony Fauci “a disaster” and suggested that other top infectious disease scientists were “idiots”.

Trump also mocked Biden for following the science during a rally on Sunday.

“Science [is] the best tool we have to keep Americans safe, while Trump’s reckless and negligent leadership threatens to put more lives at risk," the Biden campaign said.

The former vice-president later added that the line dismissing his focus on science was not an attack but a 'badge of honour'.