Second Republican debate: The biggest moments from debate stage

The seven candidates on stage all trail Mr Trump by a significant margin in the race for the party's nomination, and knew they had to do something to change the dynamic.

During a chaotic two-hour debate, they often tried to do it at once, talking over each other, the moderators, and sometimes themselves.

"Thank you for talking while I'm interrupting," Vivek Ramaswamy told Tim Scott snidely in what was a telling Freudian slip.

Here's a look at some of the key moments from the debate - and who came out on top.
 

'Donald Trump is missing in action. He should be on this stage tonight. He owes it to you to defend his record.' - Ron DeSantis
 

The Florida governor came out of the gate early with an attack that indicates he may be rethinking his refusal to tackle the former president head-on.

That strategy hinged on Mr DeSantis being an attractive alternative for 2020 Trump voters. But Mr Trump's base has been sticking with him. So Mr DeSantis may have decided he has to take the former president down if he wants any hope of catching him - or even closing the gap - in the polls before voting starts in January.

• Republicans attack Ramaswamy and 'missing' Trump
• Debate talking points as they happened

The problem for Mr DeSantis, of course, is that it's a lot harder to land blows on a candidate who is more than a thousand miles away.

The governor's digs at Mr Trump being "missing in action" did earn some praise from an unlikely fan: President Joe Biden. In a post on Thursday, the president's account on X, formerly known as Twitter, shared a clip of Mr DeSantis criticising Mr Trump's absence, adding: "That's right."

The Florida governor was steady throughout the debate, once again plugging his state record in an implicit contrast with Mr Trump. "I'm the only one up here who has been in the big fights and delivered the big victories for the people of Florida," he said.

Implicit contrasts aren't doing it so far, however. We'll see if a direct attack has more success.
 

'You're not here tonight because you're afraid to defend your record. You're ducking ... We're going to call you Donald Duck.' - Chris Christie
 

Unlike Mr DeSantis, former New Jersey Governor Chris Christie has made attacking Donald Trump the defining feature of his presidential campaign. This time he branded his nemesis "Donald Duck" as a way of mocking his decision to sit out another debate.

But the swipe landed flat with the audience.

What's more, the chaotic nature of this debate - with candidates talking over each other for extended stretches - brought them all down a peg. The backyard brawl nature of the proceedings chewed up time and may have turned off viewers.

Polls suggest Mr Trump paid no political price for his decision to ignore these debates. In fact, he appears to have expanded his lead over rivals. Nothing that happened on Wednesday night is likely to change that dynamic - and Mr Trump is reportedly planning to skip the third debate in Miami.
 

'Honestly every time I hear you, I feel a little bit dumber for what you say.' - Nikki Haley

Vivek Ramaswamy came into last month's debate riding an upswing in the polls. That put a target on the quick-tongued businessman for some of his rivals, including Mike Pence, Nikki Haley and Chris Christie.

New debate, same story. In fact, this time around even more of Mr Ramaswamy's opponents joined the fray. In what was clearly a planned attack, South Carolina's Tim Scott went after Mr Ramaswamy for doing business with China earlier in his career.

Mr Ramaswamy noted that he had stopped his China dealings, but that opened him up for a swipe by Pence, who said he must have pulled out of China in 2018 - at about the same time, he quipped, that the 38-year-old candidate started voting in presidential elections.

• Seven things presidential candidate Ramaswamy believes

Mr Ramaswamy's competitors view him as a threat. The personal nature of the attacks also suggest that some of them just don't like the political newcomer, full stop.

Last month, Ramaswamy came out of the debate a winner, boosted by the attention of his rivals. This time around, he seemed a bit more rattled by his opponents, who had more pointed attacks.
 

'I have been discriminated against, but America is not fundamentally a racist nation.' - Tim Scott
 

A month ago, Tim Scott faded into the background. His sunny, don't-go-negative strategy kept him from making headlines or momentum, while others like Ms Haley and Mr Ramaswamy prospered.

This time around, Mr Scott - sporting what looks to be an emerging goatee - was only too happy to challenge his rivals.
 

He also had one of the most personally passionate moments, as he took issue with Mr DeSantis' past comments about slaves learning valuable skills during their servitude.

"There is not a redeeming quality in slavery," Mr Scott, the only black candidate in the race, said. "America is a great country because we have faced our demons in the mirror and made a decision."

Recent reports have indicated that some deep-pocketed Republican donors who initially found Mr Scott appealing were now looking at Ms Haley as a possible Trump alternative. His debate performance on Wednesday night may give him another chance.
 

'Which one of you on the stage tonight should be voted off the island?' - Moderator Dana Perino
 

At the end of the debate, Dana Perino - one of the Fox Business moderators - noted that if the crowd of candidates does not thin before voting begins in January, Mr Trump would win the nomination. She then asked the debaters to pick a rival who they would choose to drop out first.

Nobody took the bait, and some seemed visibly angry. Their contempt was a fitting end for a tumultuous two hours, as all of the candidates repeatedly ignored the pleas from moderators to respect speaking time limits, minimise interruptions, and respect the debate rules.

In the end, it may have been the ineffective moderators who viewers wanted off the island most.