The Republican debate is starting and the candidates are walking out.

Stay tuned for more analysis from our team on the ground and in Washington DC.

Image source, Getty Images

Donald Trump has at least one good reason for not joining the debate: his lead among Republican voters is so large, he has nothing to gain by joining the fray.

The latest figures from a CBS News/YouGov survey put the former president more than 40 percentage points ahead of his nearest rival for the nomination, Ron DeSantis.

That lead grown even as Trump was hit with four separate indictments.

There's still a sizeable chunk of Republicans who say they'll vote for someone other than the former president. But with so many other candidates in the field, support is divided. It's hard to see how any of Trump's opponents will gain traction until some others start dropping out of the race.

Anthony Zurcher
BBC North America correspondent in Wisconsin

Donald Trump is not just skipping the first Republican primary debate in Milwaukee tonight, he's actively counter-programming it.

Ahead of today's event, the ex-president sat down for a pre-recorded interview with former Fox News host Tucker Carlson. It will be streaming on X, the social media platform formerly known as Twitter, during the first hour of the two-hour Republican debate.

Trump and Carlson have sometimes had a complicated relationship in the past. Both men, however, have a shared animosity for Fox News, the network airing the debate.

Carlson was dismissed from his popular evening politics show after documents from a lawsuit against Fox by Dominion Voting Systems showed the host repeatedly disparaging Fox executives - and President Trump - in messages and emails.

Trump, for his part, has a long history of clashes with Fox News, starting with what he thought was unfair treatment by the network's moderators in the first debate of the 2016 primary election season.

Both will likely be hoping that their interview tonight outshines the debate.

Read more about Carlson and Trump's hostility to Fox here.

Marianna Spring
Disinformation and social media correspondent

How is social media affecting what Americans think about their presidential candidates and next year's election?

Ahead of the debate in Wisconsin, we sat down with a panel of them to tell us what they're seeing online and how it informs their lives.

The panel agreed it's hard to escape Donald Trump on social media - whether it be memes of him dressed as a superhero or computer-generated images of him in jail scrubs.

"Everybody cares about [Donald] Trump and [President] Biden. They don't care about anything else in this country," said Andrew, a local man who says he doesn't feel represented by either candidate.

"It's like 'which one of these two is more screwed up?'"

Posts about Joe Biden come up a lot too. There are posts poking fun of his age, as well as more positive ones of him, including the widely shared "Dark Brandon" meme.

The "Sleepy Joe" posts struck a chord with some panel members.

"Joe Biden is old and sleepy," said Mary, who is originally from Wisconsin but who lives in Florida.

"He hasn't done a lot of positive things for the country. He needs to move on. And Donald Trump did some great things for the country when he was president. But Donald Trump has probably had his time as well."

Read more about the impact of social media on the elections here.

Mike Wendling
BBC News

Donald Trump has just posted on his Truth Social network, external - not a jab at political rivals but at the network hosting tonight's debate.

The former president claimed that he had a lead in polls against Joe Biden and a 50-point lead against Republican candidates but that "FOX NEWS REFUSES TO POST OR DISCUSS".

These claims have varying levels of truth. Trump is ahead in a few general election polls, but certainly not "almost all", external. He does have a commanding lead in the Republican primary but 50 points is a slight exaggeration.

Still, the post is interesting not for Trumpian bombast but as the latest chapter of his love-hate relationship with Fox.

He appeared on the network as recently as last week, but he has repeatedly slammed the conservative broadcaster for being hostile towards him or too friendly to his rivals.

Read more: Trump, Tucker Carlson and a shared hostility to Fox News

It's been a rough 24 hours for North Dakota Governor Doug Burgum.

As we reported earlier, he was taken to hospital last night after injuring his ankle during a basketball game with campaign staffers.

Less than week after collecting enough signatures to qualify for the debate, it suddenly appeared as though he might need to drop out.

With the debate fast approaching, he's now posted a photo of himself backstage in Milwaukee, sporting an ankle cast and crutches, telling voters: "I'm in".

Earlier, he told reporters he planned to "cowboy up" and remain standing at his lectern for the entire two-hour debate.

Image source, X/Burgum

Besides the three men we've already highlighted in our previous post, there are five other candidates slated to be on stage tonight.

So far, none of them have seen an outpouring of support from significant numbers of Republican voters, with poll numbers of between 1% and 3%.

Let's take a look at some of tonight's candidates, beginning with the three that currently have the highest polling numbers.

While these three are leading the pack as far as the candidates participating in the Republican debate, it's worth noting that their numbers are well below Donald Trump, which is at 62% according to a recent CBS News poll.

Sam Cabral
Reporting from Milwaukee

It is a hot summer night here, with temperatures as high as 37C (99F) - and the candidates on stage tonight are looking to turn up the heat on their own campaigns.

In an arena that usually plays host to the NBA's Milwaukee Bucks basketball games, eight presidential hopefuls will compete in the first in a series of debates before Republican voters go to the polls to choose their next nominee.

Conspicuous in his absence is Donald Trump, the runaway leader in this race, whose interview with ex-Fox News anchor Tucker Carlson will air during the debate on X, formerly Twitter.

Among those in the audience will be Donald Trump Jr, Wisconsin Senator Ron Johnson, and Florida congressmen Matt Gaetz and Byron Donalds.

The two-hour event kicks off at 21:00 EST (01:00 GMT), Trump's interview will begin five minutes earlier.

Image source, Fulton County Sheriff's Office

A busy day in Georgia - including the release of mug shots from a number of defendants - is wrapping up and the focus is shifting to tonight’s Republican debate.

It starts at 21:00 Eastern standard time – that’s 01:00 Thursday GMT.

Eight Republican candidates will be on the stage in Milwaukee, the largest city in Wisconsin, one of the key battleground states in next year’s election.

With such a crowded field, and with most of the sparring candidates polling in single digits, the pressure will be on to produce a witty zinger or a viral soundbite over the course of the two-hour debate.

The debate will be shown on Fox News and moderated by two of the channel’s veteran hosts, Bret Baier and Martha MacCallum. There will be no opening statements.

Donald Trump and his legal woes in Georgia and elsewhere will almost certainly be near the top of the agenda.

And the former president is doing some counterprogramming of his own – with a interview with former Fox host Tucker Carlson scheduled to run concurrently.

Jason Miller, a longtime Trump adviser, shares with the BBC what the campaign strategy is for skipping tonight's debate.

Miller said the candidates in the debate are “effectively an echo or cheap imitation of President Trump”.

He also said that the Trump campaign hasn't taken “off the table” the possibility of picking any one of the Republican candidates as a potential vice-president pick.

Staying in Georgia, Fulton County District Attorney Fani Willis has filed paperwork rejecting attempts to avoid arrest by Mark Meadows and Jeffrey Clark - two former Trump White House officials.

Both are asking that their cases be moved to federal courts before Friday.

Like all 19 defendants in the case, they have been given until noon that day to turn themselves in, or otherwise be issued with arrest warrants.

A judge has set a hearing for Monday to determine whether to move the cases to federal court.

In her filing, Willis notes that Donald Trump has “voluntarily agreed to surrender himself to state authorities, while other defendants have already surrendered”.

Image source, Fulton County Sheriff’s Office

We're seeing more mugshots of Donald Trump's co-defendants in the Georgia election case.

This is lawyer Sidney Powell, who is best known for an interview where she vowed to "release the Kraken".

Powell previously claimed Joe Biden won the election because of "communist money".

Powell also wrongly claimed that some voting software was created at the direction of late former Venezuelan President Hugo Chavez.

Image source, Fulton County Sheriff's Office

Jenna Ellis, a former Trump campaign lawyer who was indicted in the Georgia election case, has also turned herself in to the Fulton County jail in Atlanta.

Ellis has recently been critical of Donald Trump for not paying his co-defendants' legal fees.

She wrote on X, formerly known as Twitter, "I was reliably informed Trump isn’t funding any of us who are indicted".

She was responding to Matt Schlapp, chairman of the American Conservative Union, who wrote, “The sooner we unify behind a nominee that sooner we can use recourses to fund the defense of everyone indicted for being a Trump Republican.”

She asked, "Would this change if he becomes the nominee? Why then, not now?"

"So why isn’t MAGA, Inc. funding everyone’s defense?”

Speaking to reporters after turning himself in at the Fulton County Jail earlier today, Rudy Giuliani said that the indictment against him, Donald Trump and the other co-defendants was "a travesty".

"I am very, very honoured to be involved in this case because this case is a fight for our way of life," he said.

"It's an attack on - not just me, not just President Trump, not just the people in this indictment, some of whom I don't even know - this is an attack on the American people," he added.

One of the journalists there asked Giuliani, a former prosecutor, how it feels to be on the other side of the legal system - eliciting an angry response from the ex-New York City mayor.

"Don't interrupt me. I'm making a statement," he shot back. "If they can do this to me they can do this for you".

Image source, Fulton County Sheriff’s Office

We've just been sent a copy of Rudy Giuliani's booking photo, taken today by the Fulton County Sheriff’s Office.

He is accused of 13 crimes, including racketeering.

Emerging from a pilates studio in South Lake Tahoe, California, earlier today, Biden told reporters that he might squeeze in some time for the debates tonight.

"I'm going to try to see," he said, holding a post-workout smoothie.

"I'll get as much as I can, yes," he told reporters.

When asked what his "expectation" was for the Republican debate, he replied with a laugh: "I have none."

Sam Cabral
Reporting from Milwaukee

Image source, Reuters

To qualify for the debate stage tonight, Doug Burgum offered donors a $20 gift card for every $1 they committed to his campaign.

It worked - and the Republican National Committee announced earlier this week he had made the cut.

But earlier today, we heard that the North Dakota governor was taken to hospital last night after tearing his Achilles tendon while playing a game of pick-up basketball with campaign staffers.

Burgum showed up to the debate arena a short while ago, on crutches and with his left leg in a protective boot.

He told reporters he hopes to "cowboy up" and stand on the stage for the two-hour debate - but he will be consulting with a doctor before he makes a final decision.

Kayla Epstein
Reporting from Atlanta

As Trump's co-defendants make their way one by one to the Fulton County jail and are processed swiftly, it's worth putting a spotlight on what ordinary people often have to endure at the institution.

It is common for defendants to wait in squalid conditions for weeks, months, or even, in some extreme cases, years.

The jail provides "unhygienic living conditions" that have led to outbreaks of Covid-19, lice and scabies, a report by the Southern Center for Human Rights said. It found inmates were "significantly malnourished" and dealing with a condition called cachexia, also known as wasting syndrome.

The wait has proved deadly for several people this year alone.

Noni Battiste-Kosoko was just 19 when she died in Fulton County Jail custody in July after being arrested on a less serious misdemeanour charge.

You can read our full report on the Fulton County Jail conditions here.

Image source, Reuters