Image source, Getty Images

Who? An entrepreneur, 44, born in New York to Taiwanese parents

Key issues: Universal basic income; social media; trickle-up economic reform

One policy: Yang proposed the US government pay a $1,000-a-month "freedom dividend" to all Americans between the ages of 18 and 64 as a form of universal basic income to cushion against fewer jobs due to increased automation

Read more about Yang from our reporter Zhaoyin Feng here: The 'Asian math guy' trying to be next US president.

Tech entrepreneur Andrew Yang is about to suspend his presidential campaign, according to US media outlets. With early results coming in from New Hampshire, he is lagging well behind.

Yang did poorly in Iowa, winning just 5% of the popular vote in the Democratic caucus there.

With only 11% of precincts counted, Bernie Sanders is leading with 28% of the vote (that's just over 9,000 votes, so there's a long way to go).

Pete Buttigieg is behind him on 22%, and Amy Klobuchar on 21%.

We should have more detail in the next hour.

Healthcare is the biggest issue for New Hampshire Democrats. It was one of the most important issues for Americans nationwide in the 2018 mid-term elections and remains a key part of the Democratic platform looking ahead to November 2020.

CBS News reports that six in 10 New Hampshire Democratic voters say they want a government healthcare system to replace private insurance for all Americans.

That's exactly what candidates Bernie Sanders and Elizabeth Warren have pushed in their campaigns.

But what would that look like? We've explained it all for you here:

• Medicare for All: Can Bernie Sanders overhaul US healthcare?
• Elizabeth Warren sets out health funding plan
• Obamacare: The big election issue that's not Trump

Image source, Getty Images

The US presidential election system is a long, complicated road. Here are the basic steps:

1. Announce and register a presidential campaign with the Federal Election Commission
2. Go through the primary/caucus process to beat out other presidential hopefuls in the same party
3. The candidate who wins the most primaries/caucuses will be crowned the presidential nominee at the party's national convention in the summer before the general election
4. Campaign until Election Day on 3 November

We're currently seeing the Democrats battle it out in step two.

If a candidate wins a primary election (or caucus), they win either all or a proportion of the state's delegates, depending on party rules. Those delegates will then vote for them at the party convention.

It's a system that became widespread for the presidential election in the 1970s. Before that, a nominee was selected by party members at conventions.

Want to know more about the US election process? Check out our guide here.

Image source, Getty Images

This small, north-eastern state is small - but it packs a punch.

The swing state with a Democratic tilt is one of the first to vote in US national elections and can be a make-or-break state for candidates needing momentum to carry on. So what else should you know about New Hampshire?

• The official motto of the so-called Granite State is "Live Free or Die" - a phrase that dates back to the Revolutionary War
• And with such a bold statement on the state's license plates, perhaps it makes sense that New Hampshire is the only state where seat belts are not mandatory for adults

• It has some famous potatoes. In 2013, following efforts from an energetic class of fourth graders, state legislators designated the white potato as the official state vegetable. The students launched the campaign after learning that New Hampshire had been the first state to cultivate the white potato, in 1719

• New Hampshire resident Sarah Josepha Hale penned the famed children's poem Mary Had a Little Lamb. Hale is also credited as the "mother of Thanksgiving", for lobbying President Abraham Lincoln to create the holiday
• Other famous people from New Hampshire include comedian Sarah Silverman, Da Vinci Code author Dan Brown and actress Mandy Moore

There are some results already trickling in from New Hampshire, albeit very, very slowly. Nothing to get excited about yet (or to make quick judgments about).

The open primary process in New Hampshire is a little unusual: as we've mentioned before, people can switch party affiliation inside the polling station so they can register to vote for that party.

BBC's Gary O'Donoghue takes us to a polling station in Nashua to show us how it works.

Yes, but the Republican nomination is as close as you can get to a done deal.

Donald Trump is the second most popular president of all time among his own party members, according to Gallup, so there is almost no chance Republicans will opt for another candidate.

Having said that, one person is running against him: Bill Weld, a former Massachusetts governor who was the vice-presidential candidate for the Libertarian party in 2016.

Another Republican candidate, Joe Walsh, a radio host and former congressman, dropped out over the weekend.

Jane O'Brien
BBC News, New Hampshire

Image source, Re

Everywhere I drive in New Hampshire I see two things – deer and Tulsi Gabbard.

Looking indisputably glamorous, her billboards are everywhere. And she admits that’s the intention. The representative from Hawaii didn’t start with the name or face recognition of her better known rivals so spent her money on posters. Big posters, and lots of them.

She also rented a house in New Hampshire and drives around in a purple van (also emblazoned with her face) with her husband Abraham Williams. Eight years her junior, he’s a photographer and filmmaker and documents her campaign. They’re an informal couple, relaxed and easy going.

She comes across as warm and extraordinarily confident - but don’t be fooled by the posters. She’s tough enough to take on Hillary Clinton, who insinuated Gabbard was a Russian mole because of some of her foreign policy positions. There’s now a libel case underway.

She’s one of the many underdogs in this race, but her fans are loyal and thanks to those posters people now know who she is.

The polls are starting to close across New Hampshire - we should get the first exit polls within the hour.

Most polling began around 06:00 local time (apart from in a handful of hamlets like Dixville Notch that voted at midnight).

State officials say we could see final results as early as 21:30 local time (03:30GMT).

A poor performance in New Hampshire could spell the beginning of the end (or even the end of the end) for the likes of Deval Patrick, Tulsi Gabbard and Andrew Yang, three weeks before 14 states vote on Super Tuesday.

But one outsider who is staking a lot on New Hampshire is Michael Bennet - the Colorado senator has held 50 town hall meetings in the state in the past two months.

"We're hoping to propel Michael from New Hampshire into Super Tuesday," his spokeswoman Shannon Beckham told the Denver Post last week, external, citing growing crowds. But Mr Bennet, a moderate, has struggled to get his campaign off the ground in a crowded field.

Image source, Reuters

Campaigning has been fierce in the lead up to today's vote.

Our correspondent Gary O'Donoghue noted the Sanders campaign claimed to have knocked on 20% of New Hampshire homes in a single day over the weekend.

Here's a look at how candidates Andrew Yang, Bernie Sanders, Amy Klobuchar and Michael Bennet spent their Monday.

Image source, Google

As voters prepped for the polls on Monday, Pete Buttigieg was the top searched Democratic candidate inside New Hampshire, according to Google Trends.

And searches for the South Bend, Indiana, mayor's policies spiked a whopping 3,900% nationally in the past week.

But in the last day, former Vice-President Joe Biden has been the most searched at 33%, followed by Buttigieg at 23% and Bernie Sanders at 19%. (All the other candidates are in single digits.)

Anthony Zurcher
BBC News, New Hampshire

The Democrats are in the spotlight the night of the New Hampshire primary, but the evening before - at least in downtown Manchester - it was all about Donald Trump.

As he did in Iowa, the president held one of his raucous rallies, filling a 12,000-seat arena, with a spillover crowd of several thousand watching in the evening chill outside on jumbo screens.

The less hardy gathered at a Murphy’s, an Irish bar across the street, which switched televisions normally tuned to hockey and basketball to the president’s speech.

Bill Driscoll, who lives in Manchester, said he’s more excited about Trump now than the day he was elected. While he acknowledged he sometimes wishes the president would “shut up,” as a conservative he was happy with his policies in office.

In fact - as voters are allowed to do in New Hampshire - he had switched his party affiliation to Democrat for the primary in order to vote for Bernie Sanders - who he thinks would be the easiest opponent for the president.

Sporting a pink “women for Trump” hat, 37-year-old Sonia Pratt from nearby Concord said she had never bothered to vote until Trump came along. She said the president is different than the other politicians.

“He’s real,” she said. “He may be a billionaire, but he’s also one of us. He gets right down on the level of the people, rather than in some ivory tower.”

Four years ago Hillary Clinton narrowly defeated Trump in New Hampshire by a few thousand votes. Despite its small size it will once again be a pivotal battleground on an electoral map that contains only handful of truly up-for-grabs states.

No.

Many of the problems in Iowa were down to a new app that recorded the results of each caucus. New Hampshire should avoid any such problems - there’s no app being used this time, and (because it’s a primary) everyone’s vote has been noted using good old fashioned pencil and paper.

Gary O'Donoghue
BBC News, Nashua, New Hampshire

For much of the day, in the Ledge Street elementary school gym, there's an overpowering sweet buttery smell that can only be popcorn.

That's because Amy and Uttara - both teachers at the school - have been cooking up great vats of the stuff to keep the workers going at this polling station in Nashua, New Hampshire.

As well as the popcorn, Amy is selling muffins and brownies to voters as they come in and out - no prices, just what you feel happy to pay: all proceeds to the drama department at the school for a new sound system.

Meanwhile Fred Davis, the polling station moderator ′the guy in charge′ roams across the gym floor making sure all is well - directing voters through each step of the process.

He's confident they'll exceed the thousand or so ballots they took in 2012 - the last really comparable election when there was an incumbent president and a competitive primary in the other party.

Image source, EPA

By mid-afternoon, the figure was already well over 1,100 and staff were confident they could be looking at a 40% jump in their turnout by the time the polling station closes at 20:00.

Husband and wife Michael and Pat Miceli tell me how they finally decided to vote for Amy Klobuchar. But it wasn't easy.

"I wish we could take a little from each of them and make a brand new candidate with all the best bits," says Michael.

But as they move off, James, wearing a stripey flat cap, tells me he has no doubt that Joe Biden is the best candidate: "he's just a regular Joe!"

Image source, AFP

The Fox News presenter is a hero to conservatives for his loyalty to President Trump and his outspoken lambasting of Democrats.

So he might have been the last person you'd expect to see in New Hampshire at a Joe Biden event, where he was spotted by the BBC's Katty Kay speaking to Biden devotees.

What was he asking them?

Watch below as Katty unravels the mystery.

Image source, Getty Images

It seems like a political lifetime ago, but it has been just eight days since our eyes were on the Iowa caucuses - the first major contest on the way to the White House.

So what happened?

• The night of the caucuses was plunged into chaos by issues reporting results

• The Iowa Democratic Party Chairman blamed the delay on a coding error in a mobile app used to report results
• It took three days for the results to be confirmed, with the chairman of the Democratic National Committee calling for a review of the vote totals
• Finally, with 100% of precincts reporting, Pete Buttigieg was named winner by a tiny margin, with Bernie Sanders trailing close behind
• Both are now leading the race to become the Democratic nominee for president - but there is a long way to go yet

Jane O'Brien
BBC News, New Hampshire

Image source, Getty Images

New Hampshire can make or break a campaign as former Vice-President Joe Biden may be about to find out.

He never caught up with his closest rival Bernie Sanders and has virtually conceded defeat here, leaving the state before the polls close to travel to South Carolina, where he hopes to do better.

So what went wrong? 90 percent of any job is turning up, and Biden was conspicuous by his absence compared to the other candidates. In a state defined by retail politics, that was a mistake.

His personal energy levels also left a lot to be desired. I watched him at a campaign event at the weekend and thought he looked and sounded like an ageing uncle at a family gathering who tells the same anecdotes over and over.

One man who’d supported Biden for decades told me he saw little evidence of the man who could have beaten Trump 20 years ago. "I want to see fire and fury," said a woman who left the event still undecided who she would vote for.

By leaving the state prematurely, he has given New Hampshire the impression he’s given up on them. It now looks likely that voters here have given up on him.