Republican presidential rivals Ron DeSantis and Nikki Haley will square off on Wednesday in their first head-to-head debate as they fight to emerge as the clear alternative to frontrunner Donald Trump in the race for the party's White House nomination.
DeSantis and Haley have little time left to halt Trump's march towards the nomination, with the former U.S. president holding sizeable leads in opinion polls just five days before voting begins in Iowa on Monday.
In their battle to become the lone challenger to Trump, Haley and DeSantis have been intensifying attacks on each other in recent days and are expected to unleash furious salvos in the CNN debate, which begins at 9 p.m. ET (0200 GMT).
Wednesday's prime-time debate in Des Moines will allow Haley, who served as United Nations ambassador under Trump, and DeSantis, the governor of Florida, to draw the sharpest contrasts between themselves yet after other candidates failed to qualify to join them on stage.
Beating each other out for second place in Iowa will be critical in their efforts to turn the race into a one-on-one match-up against Trump. The Republican nominee is expected to take on Democratic President Joe Biden in November's election.
"The debate will be their last and best chance to tell Iowa caucus-goers why they deserve to be the alternative to former President Trump and why they should have a head-to-head shot at him," said Jimmy Centers, an Iowa-based Republican strategist unaffiliated with a campaign.
Trump will once again skip the debate, the fifth of the nominating cycle. He will hold a rival event, a town hall on Fox News, at the same time and close by in Des Moines, Iowa's capital.
Trump's Iowa campaign has been far more organized and heavily staffed than his 2016 effort, when he placed second in Iowa to U.S. Senator Ted Cruz.
Trump mostly has avoided smaller, more intimate gatherings in bars and school gyms, the traditional staple of Iowa campaigns, opting instead to deploy allies to hold such events on his behalf while he headlines large rallies.
His campaign uses the events to scoop up personal information that allows for follow-up calls and texts to remind supporters to show up for the caucuses.
DeSantis, meanwhile, is banking his campaign on a strong showing in Iowa. He has visited all 99 counties and has been wooing evangelical Christian voters, a powerful voting bloc in the state.
Haley has pitched voters in Iowa on her more pragmatic approach to issues such as abortion, and on her hawkish foreign policy, a stance at odds with the more isolationist Trump and DeSantis.
Asked to comment on the debate, a Haley spokesperson focused on Trump instead of DeSantis.
"With the debate stage down to just two, the time for Donald Trump's hiding is just about over," spokesperson Olivia Perez-Cubas said.
The DeSantis and Trump campaigns did not respond to a request for comment.
