Key moments from Republican presidential debate so far

We're more than halfway through the first Republican debate, and so far it's a fight to see who can stand out on a crowded - and loud - stage.

Eight candidates are vying to prove to the American public that they should be the party's presidential nominee.

That's a lot of competing voices - and, at times, a lot of chaos. Here are some moment that stood out, so far.

It didn't take long for the first animated clash between candidates on the debate stage, although the identity of the participants may come as a bit of a surprise.

Former Vice-President Mike Pence, in his first chance to make remarks, took aim at first-time political candidate Vivek Ramaswamy, highlighting his own long experience in politics and saying it wasn't time for a rookie in the White House.

"Now is not the time for on-the-job training," he said.

Mr Ramaswamy, a tech entrepreneur, is offering a decidedly different attitude on the debate stage so far, smiling broadly and poking fun at his opponents. Part of that is his status as a political outsider. The other part is that his campaign is already outperforming expectations and he is, in effect, playing with house money.

The veteran politician dog-pile on Mr Ramaswamy is just beginning, however. Shortly after the exchange with Pence, former New Jersey Governor Chris Christie entered the fray, saying Mr Ramaswamy was "a guy who sounds like ChatGPT".

For politicians who have worked their entire life to get on this debate stage, Mr Ramaswamy's presence - at the centre of the stage no less - must be irksome.

Abortion is a delicate issue for Republicans. It is an issue that their evangelical base cares about deeply. They believe abortion is murder and should be eradicated across the country. More politically practical Republicans, however, understand that the American public as a whole does not support stringent abortion bans - and the issue pushes moderate voters to back Democratic candidates and motivates Democrats to head to the polls.

That division within the party played out prominently on the Republican debate stage, as former Vice-President Mike Pence, who is decidedly in the anti-abortion camp, clashed with former South Carolina Governor Nikki Haley.

Ms Haley, the only woman on the stage tonight, represented the more pragmatic approach, saying that while she's "unapologetically pro-life", the Republican party needs to stop "demonising" the issue and build "consensus" when it comes to a potential federal ban.

Ms Haley's position may play better in next year's general election at swaying moderate voters, but Mr Pence is betting his campaign on the proposition that his outspokenness on abortion will win him the kind of evangelical support to life him in the Republican primaries.

"We can win," he said. "You got to do what you think is right. I believe in a culture of life."

Ukraine has been a growing source of division within the Republican Party, which has been shifting away from the internationalist foreign policy of the George W Bush years to Donald Trump's America First nationalism.

That division played itself out dramatically on the debate stage, as Mr Ramaswamy - who has said the US should end military aid to Ukraine - clashed with his more established Republican opponents.

Mr Pence drew comparisons between US support for Ukraine to American efforts to combat the Soviet Union during the Cold War, even echoing an old Cold War refrain: "We achieve peace through strength".

Then it was Ms Haley's turn.

"You have no foreign policy experience and it shows," the former UN ambassador told Mr Ramaswamy.

The reality, however, is that recent polls show that Mr Ramaswamy's view - that the US is giving too much to Ukraine - is one held by the majority of Republican voters. The ground is shifting in the party, and candidates like Mr Pence and Ms Haley are going to have to change voters minds if they want the issue to be a winner for their campaigns.