Anthony Zurcher
BBC North America correspondent

Beto O’Rourke, the former congressman from El Paso, Texas, ran a surprising strong challenge to incumbent Texas Senator Ted Cruz in 2018.

He then launched a campaign for the Democratic presidential nomination in 2020 that started with considerable fanfare, but later flamed out before even one primary ballot was cast.

Now he's seeking to unseat two-term Texas Governor Greg Abbott and become the first Texas Democrat to lead the state since 1994.

It’s a tall task for O'Rourke, who has trailed his Republican opponent in the polls - sometimes by double-digits - for months.

Image source, Reuters

Although he has built a grass-roots campaign in the state that has knocked on five million doors and raised more than $66m in donations, Abbott has a war chest of more than $100m, a battle-tested Republican political organisation and the political winds at his back in an electoral environment that favours conservatives.

While O'Rourke has criticised Abbot’s positions on abortion, gun control and the environment, Texas voters appear more interested in the economy, undocumented immigration and crime.

While most 2024 Republican presidential speculation is swirling around Donald Trump and Florida Governor Ron DeSantis, a comfortable win by Abbott could set the Texan up for his own try for the White House.

He has proven he can raise the kind of money needed for a national campaign, and he has been active and outspoken on key issues for the party’s primary voters.

Iqra Farooq
BBC Newsbeat

BBC Newsbeat asked young US expats in London about watching the midterms unfold from abroad.

Olamide Noah, from California, recalls anxiously watching the results of the presidential election two years ago from the UK.

“Obviously, who's elected has a direct effect on the people that I love,” she says.

“I'm kind of getting that anxiety feeling again, constantly checking the news, seeing where the polls are, to try to anticipate the outcome.”

Daniel Fink, from Philadelphia, says this is the first time he’s lived overseas during an election.

“It feels much more intense,” he says.

“You know your vote is so much more important because the absentee ballots, abroad ballots, are the ones that often come in at the very neck-end of the counting.

“So, it's a very interesting feeling.”

Kimberly Winberg, from New Jersey, who has lived in the UK for six years, says she finds the division in US politics upsetting.

“It's really sad to be an American living abroad and people attacking each other over what’s on the news,” she says.

“I think back to the time of post 9/11 and I miss seeing that unity, and I hope we can get to that place again.”

Peter Bowes
Reporting from Santa Clarita, California

Polling day in southern California started with a downpour. Some neighbourhoods are under mandatory evacuation orders with the threat of mudslides and flash flooding in areas where wildfires burned earlier in the year. The roads are a mess.

I'm at a polling place in Santa Clarita where there is a tight Congressional race. It is very quiet here, a reminder that more than four million people across California have returned mail-in ballots

Voters tell me they are worried. A young mother says violent crime is her biggest concern and that she has started carrying a concealed knife and pepper spray to fend off potential attackers.

She notes that crime is an issue in Los Angeles suburbs that once had a reputation for being safe.

The Latino owner of a landscaping business meanwhile says that, for him, the election is all about the cost-of-living crisis. His customers are reluctant to commission new projects and he blames the Democrats.

Image source, .

Republican Ron DeSantis, who is standing to be re-elected as governor of Florida, has also voted in the election.

Having been sworn in as governor in 2019, the 44-year-old has become one of the most recognisable figures in the Republican camp.

His stance on LGBT rights, "woke" education, Covid-19 restrictions and border security have made him popular with much of the Republican base.

He is also widely tipped to run for the Republican presidential candidate in 2024 - although, so far, he himself has not announced his intention to run for president.

Ahead of election day, polls indicated DeSantis had a comfortable lead against his rival in the Florida governor race, Democrat Charlie Crist.

Read more about DeSantis here.

Gary O'Donoghue
Reporting from Atlanta

A judge in Georgia has ordered one state county to extend the deadline for returning mail-in ballots for hundreds of people.

A clerical error in Cobb county north of Atlanta meant just over 1,000 people did not get sent their ballot papers.

Some have voted in person and others have been sent ballot papers by overnight mail.

But instead of 19:00 on election day, those voters will have until 14 November to get their papers back, as long as they are dated by today.

State officials have blamed “human error” for the problem.

Current waiting times to vote in Georgia are around two minutes according to election officials.

Former President Donald Trump has spoken outside his local polling station in Palm Beach, Florida, where he was to cast his vote, alongside his wife Melania.

Speaking to reporters, he said: "I think we're going to have a great night."

Asked whether he would stand for the presidency again in two years' time, he said: "I think Tuesday will be a very exciting day for a lot of people."

Chelsea Bailey
Reporting from Washington

Election officials in Arizona's hotly contested Maricopa County say they're working "as quickly as possible" to address technical issues with voting tabulators.

"We've got about 20% of the locations out there where there's an issue with the tabulator, where some of the ballots that after people have voted they try and run them through tabulator, and they're not going through," said County Chairman Bill Gates in a video posted by the elections department.

He added they were trying to fix the issue as soon as possible, but if voters encountered difficulties, they could also put their ballot into a secure box as a back-up. He also said people could go to another voting location in the county to cast their ballot if they preferred.

This morning, a video quickly spread online showing , externalelection officials in Anthem, Arizona, attempting to reassure voters after a machine went down. Though the worker insisted all ballots would be counted - even if by hand - voters standing in the queue were upset.

In a country as big as the United States, technical difficulties on voting days are inevitable. But in today's political climate, where voter mistrust is at an all-time high, any technical difficulties on election day could add fuel to false claims of election fraud.

Image source, .

Back to the key races in the elections now. Perhaps speaking to the Democrats uphill struggle to retain control of Congress, one of their most experienced politicians in Ohio is facing stiff competition in a Senate race from a relative outsider in Republican terms.

The midwestern state voted solidly Republican in two consecutive presidential elections and this year’s race was not originally thought to be a close one.

But the contest between serving congressman Tim Ryan and Donald Trump-backed JD Vance looks to be going down to the wire. Both men cast their ballots earlier.

Image source, Reuters

Ryan, who has been a Democratic member of the House of Representatives since 2003, had an unsuccessful run for the presidency in 2020 and a failed challenge to House Speaker Nancy Pelosi's position in 2016.

He is currently neck and neck with JD Vance - a venture capitalist and author of 2016 best-selling memoir Hillbilly Elegy - who has been through a political journey from staunch opposition to enthusiastically courting the support of Donald Trump.

Image source, Twitter/Tim Ryan

Marianna Spring
Disinformation and social media correspondent

As US voters head to the polls, a number of recent news events have been shaping their social media feeds. I have been investigating what voters are recommended online at a turbulent time for US politics.

I've created social media accounts belonging to five fake characters, who reflect views from across the political spectrum in the US.

The voters were created to represent views from across the US political spectrum, based on data gathered by the Pew Research Centre. I gave each of them a profile on Instagram, Facebook, TikTok, YouTube and Twitter, with names and computer-generated photos.

While these profiles can't offer an exhaustive insight into what every US voter could be seeing - and they don't have friends or followers - they do give us a snapshot of what voters across the political spectrum are being exposed to.

While social media sites say they are committed to tackling disinformation and hate on their platforms ahead of the poll, for my undercover voters, misleading and violent posts appear to have only increased in recent weeks.

• Read more about the profiles I set up

Britney is one of the five profiles I've created: I open up her Instagram and click on an account that's been recommended in her feed. I'm greeted by a meme falsely declaring that President Joe Biden never really won the 2020 election, and several others targeting named female politicians with misogynistic comments and abusive language.

Over the next few hours, I'll introduce you to our Undercover Voters and what they've been recommended online.

Read more here.

Barbara Plett Usher
North America correspondent, reporting from Virginia

Voting is under way in the United States for midterm elections - with control of both Houses of Congress in the balance.

Turnout is expected to be high as Republicans try to gain a majority in the House of Representatives and the Senate, paralysing President Biden's agenda for his remaining two years in office and potentially paving the way for Donald Trump to return to the White House.

Political operatives from both parties say there’s a good chance Republicans will take back control of the House of Representatives.

There’s a much tighter competition for the Senate and attention is focused on a handful of crucial races that are too close to call – in Georgia, Pennsylvania and Nevada; historically it's normal for the president’s party to lose control of one or both houses of Congress during the midterms.

What’s not normal is that roughly half the Republican candidates at state and federal levels have cast doubt on the election system itself.

They claim the presidency was stolen from Donald Trump in 2020, so the Democrats have cast this election as a defining vote for US democracy even as Trump is strongly signalling a comeback.

Image source, EPA

It's a big day for millions of Americans, so if you're looking to get out and cast your ballot before polls start closing, here's what you need to do.

Find out where you can vote

You can find out where you can go and vote on your state's election website, external. Check if you need to take any ID along with you here, external.

Check when your polling station closes

Voting hours are different in each state. You can look up what time your polling station closes on your state’s election website. Remember, you can't vote online in any federal elections.

Can you still register to vote?

Lots of US states offer same-day voter registration - you can check here at Vote.gov, external. If your state is on the list, you'll need to take your photo ID and proof of residence along with you.

Can you still post your ballot?

You can't request a mail-in ballot anymore, but if you already have one, you can still return it by the deadline, which varies by state, external. The ballots can also be delivered in person to a secure drop box near a polling site or government building.

Image source, .

The two candidates vying to be one of Pennsylvania's Senators, Democrat John Fetterman and Republican Dr Mehmet Oz, cast their own votes a little earlier.

With the battle to control the upper chamber of Congress's 100 seats going down to the wire, the race looks set to be one of the most important results of these midterms.

A recent poll gave Fetterman a 51-49 lead - well within the margin of error - but patience will be required for those eagerly awaiting the result, which could take days to finalise because state law does not allow election officials to start processing postal ballots before today.

Image source, EPA-EFE/REX/Shutterstock

The race has been characterised by controversy, with Fetterman holding a commanding polling lead before he suffered from a stroke earlier this year - which kept him from campaigning until he agreed to participate in a challenging televised debate.

Oz, a celebrity TV heart surgeon, attacked Fetterman over his ability to do the job given his health, even going so far as to suggest Fetterman would not be ill if he "had ever eaten a vegetable in his life".

Oz came to prominence through appearances on The Oprah Winfrey Show in the early 2000s but Oprah herself recently endorsed Fetterman.

Image source, Reuters

If you want to follow the drama as it unfolds, we've got you covered.

The BBC News website will have election results as they come in overnight, and our live page will have the latest reaction and analysis from correspondents in the US and around the world.

We're tweeting every result on @bbcworld, external too, along with expert analysis.

On TV, our special results programme is being hosted by Katty Kay and Christian Fraser in Washington. It'll be broadcast on BBC Two, the BBC News Channel and BBC iPlayer from 18:15 ET (23:15 GMT) until 02:30 ET (07:30 GMT).

There's more on our results offering here.

Voting day is in full swing, with millions of Americans casting their ballots across the country.

These elections are hugely consequential, with President Joe Biden's Democrats fighting an uphill battle to retain control of the US Congress.

Republicans are tipped to take control of the House of Representatives, but the fight for the Senate remains on a knife-edge. Governors races are taking place in dozens of states

We'll be bringing you live updates, analysis and all the results on this page as we get them. Stay with us.

Image source, Getty Images