Republican debate: Rivals prepare to extinguish Donald Trump's fiery campaign in second GOP clash

As the 11 candidates head to the stage at the Ronald Reagan Presidential Library, Tim Walker weighs up the fight ahead

Candidate photos are displayed on podiums before the start of the CNN Republican Presidential Debate, in Simi Valley, California (Getty Images)

As the GOP presidential field squeezes onstage at the Reagan Library in Simi Valley, California for their second debate tonight, it is the election-winning vim of the venerated 40th President that they will all be hoping to emulate. Pundits have predicted a more combative exchange than at last month’s first debate in Ohio, when many of the candidates appeared content simply to weather the bluster of Donald Trump, safe in the belief that his fiery campaign would soon flame out.

Instead, as the 15 remaining contenders converged on Southern California, a poll this week from USC and the Los Angeles Times found Trump leading the Republican field in the Golden State, with 24 per cent of Republicans saying they would vote for him. This time, his rivals will treat him more like the front-runner he is, and try their best to tear him down from his perch.

CNN, the broadcaster behind tonight’s debate, intends to give them that opportunity, by inviting the candidates to engage and argue with one another in a format unlike their previous exchange, when it was the Fox News anchors who pressed the candidates on personal and policy questions. Tonight’s moderator, CNN anchor Jake Tapper, told the New York Times that he hopes to allow the candidates to “fight it out” among themselves.

Donald Trump made quite the impression during the first debate (Mandel Ngan/AFP/Getty Images)

That is a challenge to which the more traditional candidates must rise if they hope to halt the march of the outsiders in the coming months. Former Florida Governor Jeb Bush, the GOP establishment favourite, will attempt to counter Trump’s repeated claims that he is a "low energy" candidate, perhaps by contrasting his suite of policy proposals with Trump’s rhetoric – so far, The Donald’s only stated policy promise is to build a wall the length of the US-Mexico border.

Wisconsin Governor Scott Walker, a top seed at the start of this presidential race, has turned out to be a lacklustre national campaigner, and must deliver at least a noticeable performance tonight if he is to persuade voters that he is a viable candidate. Three months ago, a Quinnipiac poll had Walker as the favourite to win the crucial Iowa primary. This month, the same pollster measured his support in the state at a diminutive 3 per cent, putting him all the way back in 10th place.

Ben Carson has been creeping up on Donald Trump in the polls (Getty Imags)

In recent polls, it is neither Bush nor Walker that has gained on Trump, but another political novice, former neurosurgeon Dr Ben Carson, who used to say a prayer before his difficult operations and has proved popular among Christian conservatives. Collectively, Carson and Trump command the support of more than half of Republican-leaning voters, according to some polls.

Another new face on the debate stage this evening will be former Hewlett-Packard CEO Carly Fiorina, who distinguished herself sufficiently during Fox News’s so-called "kids' table" debate in August to win promotion to the top tier. The only woman in the race, Fiorina has promised that Trump will be "hearing quite a lot" from her at the debate, after he disparaged her appearance in a recent interview with Rolling Stone.

Carly Fiorina's popularity has grown since her performance in the first debate (AP Photo/John Minchillo)

Tonight’s CNN debate also includes an undercard event, beginning at 3pm Pacific Time (6pm EDT/11pm BST), and featuring just four hopefuls: South Carolina Senator Lindsey Graham; Louisiana Governor Bobby Jindal; former New York Governor George Pataki; and former Pennsylvania Senator Rick Santorum. The main event at 5pm will feature 11 candidates: Trump; Bush; Walker; Carson; Fiorina; Texas Senator Ted Cruz; Florida Senator Marco Rubio; Ohio Governor John Kasich; New Jersey Governor Chris Christie; former Arkansas Governor Mike Huckabee, and Kentucky Senator Rand Paul.

Rick Perry, the former Governor of Texas, dropped out of the presidential race last week citing his campaign’s financial difficulties. Former Virginia Governor Jim Gilmore, who appeared on the Fox undercard, has fallen below 1 per cent in the polls, meaning he misses out on a place even at the CNN kids’ table. The debate will take place against the backdrop of President Reagan’s decommissioned Air Force One plane, now a permanent fixture at the Library, and with a live audience of around 400 people. Fox News broke records with the broadcast audience for the first debate; CNN doubtless hopes to do the same.