Sarah Smith
North America editor

Despite the polls suggesting she is around 30 points below Donald Trump, Nikki Haley is fighting hard in her home state of South Carolina, insisting that she will stay in this race even if she suffers a significant defeat tonight.

She says voters want a change from Trump and Joe Biden, describing them as the "two least liked politicians in America".

Donald Trump is so confident of victory he was not even in South Carolina as polls opened this morning - he instead gave the headline speech at a conservative conference in Washington.

There is not one single state where it looks as though Haley can beat Trump.

But she has the funds to carry on.

Her campaign raised more money than her opponent's last month - from donors who want her to keep making the case against Trump even if they don’t believe she can ultimately defeat him.

Anthony Zurcher
BBC North America correspondent

In his speech to CPAC, Donald Trump painted a dark picture of America under President Joe Biden in what could be a preview of his general election message to voters.

"Hordes" of undocumented immigrants entering the US. "Ruthless gangs" marauding city suburbs. "Weaponised" law enforcement hunting conservatives. Antifa protesters (short for anti-fascist) terrorising the streets.

It was reminiscent of Trump’s bleak 2017 inaugural address, in which he promised to end an "American carnage" of blood-soaked cities, empty factories and a crumbling infrastructure.

Trump served four years in office, but the carnage remains, it seems. And on Saturday he warned CPAC attendees that things will only get worse if he doesn’t win in November.

“Our country is being destroyed, and the only thing standing between you and its obliteration is me,” he said.

The CPAC crowd, dominated by Trump loyalists, cheered in approval, as Trump promised retribution – with a twist.

"Your victory will be our ultimate vindication,” he said. “Your liberty will be our ultimate reward. And the unprecedented success of the United States of America will be my ultimate and absolute revenge."

It sets up a general election where both Biden and Trump warn of the direst consequences if they are defeated. In what promises to be a close election, half the country will believe the worst is in store no matter which candidate ultimately prevails.

Bernd Debusmann Jr
Reporting from CPAC

Image source, Reuters

Donald Trump has just finished his speech, giving an adoring crowd an hour and a half's worth of commentary in which he touched upon everything from foreign leaders he counts as allies to a lengthy story about a nerve-inducing flight into Iraq.

In-between a long series of jokes - most of which landed extremely well with the crowd - and personal jabs on Biden's memory and competence, he delivered an outline of another term in the White House, including mass deportation of undocumented migrants and plans to "drill, baby, drill" for oil and gas.

What he didn't mention is just as notable: not once did he say Nikki Haley's name.

Only briefly did he mention the primary - at the start and finish.

Image source, Reuters

Away from Donald Trump for a moment and his rival, the Republican hopeful Nikki Haley, has been seen casting her vote in the South Carolina Republican primary.

She attended a polling station on Kiaweh Island with mother Raj, son Nalin, daughter Rena and Rena's husband Joshua.

Haley reportedly helped her mother cast her vote, before casting her own.

She told reporters afterwards that she'd be "campaigning all day today, and then we're going to keep going all the way through Super Tuesday".

"I am not going anywhere," she said. "I'm going to make sure that we give Americans a choice."

Image source, Reuters

Bernd Debusmann Jr
Reporting from CPAC

Image source, Getty Images

Donald Trump's focus on President Biden is receiving a warm welcome from the CPAC crowd.

The conservative political conference has become very much a Trump-dominated affair in recent years.

"To achieve our future, we have to throw off the chains of the political class, and that begins with crooked Joe Biden," the former president says.

"That begins with telling him: 'You're fired!'"

It's one of several moments greeted with standing applause.

From where I'm sitting, I can see red "Make America Great Again" hats sprinkled throughout the packed ballroom.

After nearly every comment made by Trump, shouts of "yes!" and "we love you!" can be heard. Many attendees are nodding their heads as he speaks.

He's still not mentioned Nikki Haley. From here, the primary in South Carolina seems like a distant afterthought. Everyone is thinking and talking about November.

Bernd Debusmann Jr
Reporting from CPAC

Former President Trump's speech focuses heavily on November's election and his likely rematch with Joe Biden.

It may be a primary day, but this speech is well past that. He clearly believes he will be the nominee.

Trump starts with an important issue for many voters - the border - before moving onto the economy, crime and what he described as the potential of a third world war.

"The only thing standing between you and [America's] obliteration is me," he tells the crowd.

He describes Biden as "most incompetent president in the history of our country", to loud applause.

On foreign policy, Trump paints himself as a bulwark against America's decline in the world, suggesting China wants both military and economic domination.

Reflecting on his own legal issues, Trump repeats unsubstantiated claims that he is the target of political persecution. He tells the CPAC crowd he is "a dissident".

"I've been indicted more times that Alphonse Capone," he says, referring to the American gangster.

Bernd Debusmann Jr
Reporting from CPAC

Image source, CPAC/Rumble

In the opening minutes of his speech, Donald Trump acknowledges the South Carolina primary - but he hasn't mentioned Nikki Haley yet.

"Big election going on today," he says. "You've probably read a little bit about it."

He says he should have been somewhere else - for example campaigning in the state - but says he told them, "no, I'm sorry I have to be at CPAC today".

Bernd Debusmann Jr
Reporting from CPAC

Image source, CPAC/Rumble

To the sound of thunderous applause and an introduction describing him as the "next president" of US, Donald Trump has just strolled onto the stage at CPAC.

Dressed in his characteristic suit and red tie, Trump already looks like a man triumphant.

In his speech - excerpts of which have been seen by US outlets including the New York Times and the HIll - Trump is expected to outline his vision for a second term in office, including his plan for the US-Mexico border and the economy.

It remains to be seen whether he will comment on Nikki Haley or the South Carolina primary. If he does, he will be one of only very few speakers at CPAC to do so.

Stay with us as we bring you more updates.

According to the CPAC agenda, Trump was due to speak at 13:00 EST (18:00 GMT) .

As of yet, we're still waiting for him to appear, with songs (everything from Johnny Cash to showtunes) being played in the meantime.

The slogan for this year's CPAC is "where globalism goes to die" - and speakers so far this year have included the presidents of Argentina and El Salvador, former Trump strategist Steve Bannon, the UK's former PM Liz Truss and the honorary president of Reform UK, Nigel Farage.

Tom Bateman
Reporting from the conference

Image source, Reuters

This used to be a "big tent" event for conservatives of all stripes; these days it’s more or less a Trump convention.

An ad repeatedly plays on the giant plasmas between speeches asking people to vote - not on whom Republicans should nominate for the election - but simply: “Who should be President Trump’s vice president!”

I’ve been watching speeches in the event hall and chatting to delegates beside the Trump bus in the exhibition rooms.

Two big themes keep coming through: A deep suspicion of multilateral global institutions seen as trying to destroy national sovereignty; and so-called “wedge" issues that now form a dominant part of political campaigning - opposition to gender identity, transgender rights, or abortion for example.

Much of this was pithily projected in the speech by former UK Prime Minister Liz Truss who said: "The very basis of Western civilisation is being undermined”.

But watching the stage I was struck by how little debate or challenge was encouraged in the panel events. All political conventions are tribal, but this one never got much further than a platform for polemics.

It's a big day for the Republican Party.

The day officially started at 07:00 ET (12:00 GMT) when South Carolina polls opened in the primary. We've got reporters across the state and will bring you the latest from there a bit later.

But Donald Trump is not in South Carolina yet - he will shortly be speaking at the Conservative Political Action Conference just outside Washington DC.

Then later he's heading to a rally in Columbia, South Carolina. His rival Nikki Haley will hold her rally in Charleston, South Carolina.

Polls close state-wide at 19:00 ET (00:00 GMT). We don’t know how quickly the results will come through, but Trump has a 30% lead in polls so it could happen fast.

In just over five minutes, former President Donald Trump is set to speak at the Conservative Political Action Conference (CPAC).

The annual event is just outside of Washington DC, and has been transformed in recent years into a heavily pro-Trump affair, a reflection of his takeover of the Republican Party.

Will he talk about today's South Carolina primary and Nikki Haley? Let's wait and see.

Francesca Gillett
Live reporter in Washington DC

Image source, AFP/Reuters

We’re now more than five weeks into the US election race - and today's the day Republicans in South Carolina get to vote for who they want to be their candidate.

Donald Trump is the front-runner in the contest - just as he was last month at the start of the race in Iowa.

He's about to speak at the Conservative Political Action Conference near Washington DC - an event for conservatives across the US but which is now a big pro-Trump affair.

But Nikki Haley is not giving up - despite polls showing her badly trailing the former president.

There was speculation that she might drop out of the race, but earlier this week she told a rally: "“I’m not. Far from it."

Stick with us over the next 24 hours as we bring you the key moments and all the action.