TUSCALOOSA, Alabama - Former U.N. Ambassador Nikki Haley was the subject of repeated attacks during Wednesday's Republican presidential debate, as Florida Governor Ron DeSantis sought to blunt her momentum just weeks before the party's first nominating contest in Iowa.

The two rivals were vying to emerge as the chief alternative to the absent former President Donald Trump, who has maintained a commanding lead in opinion polls ahead of Iowa's Jan. 15 contest.

The debate, which also included tech entrepreneur Vivek Ramaswamy and former New Jersey Governor Chris Christie, saw a flurry of insults interspersed with discussions of the Ukraine war, the Israel-Hamas conflict and the U.S. southern border.

But aside from Christie, who has put criticisms of Trump at the center of his campaign, none of the candidates on stage in Tuscaloosa, Alabama, appeared willing to go after the front-runner directly, a reflection of Trump's continued popularity among the Republican base.

Asked about Trump's comments at a Fox News town hall on Tuesday that he would not be a dictator during a second term, except on "day one," Christie called him "an angry, bitter man" intent on retribution and repeatedly demanded DeSantis say whether he believes Trump is fit for office.

DeSantis deflected several times, instead referring to the 77-year-old Trump's age and arguing the presidency is better suited for someone younger.

Haley also offered only muted criticism, saying Trump represented "chaos" and blaming him for adding billions of dollars to the national debt.

Instead, DeSantis and Ramaswamy spent most of their time taking shots at Haley, who has risen in polls and drawn increased interest from donors on the strength of her previous debate performances.

"She caves anytime the left comes after her, anytime the media comes after her," DeSantis said of Haley during the first answer of the evening, as he sought to explain why voters should back him despite Trump's dominant position.

DeSantis boasted about legislation he passed in Florida banning gender-affirming medical care for transgender youth and accused Haley of opposing the law, an assertion Haley denied.

"He continues to lie about my record," she said.

TRUMP ABSENT AGAIN

The debate, which aired on the young cable news network NewsNation and the CW network, featured the smallest field thus far, as the Republican National Committee has raised the polling and donor requirements for each event.

As with the first three debates, the former president - leading by more than 40 percentage points in most opinion polls - skipped Wednesday's event, instead attending a fundraiser in his home state of Florida.

His campaign released a new advertisement during the debate portraying Biden as weak, signaling he is focused on the general election and not his Republican rivals.

Trump's absence deprived them of an opportunity to confront him face to face and again sent the message he deems his challengers unworthy of his attention.

Haley has cut into DeSantis' lead in national polls while building a substantial edge in New Hampshire and her home state of South Carolina - crucial states because they are among the first to pick a nominee.

The two are effectively tied in Iowa.

With no additional debates currently scheduled, Wednesday's televised clash could be the last chance for Haley or DeSantis to land an enduring blow in front of a national audience.

Ramaswamy, who has aligned himself closely with Trump, teamed up with DeSantis to go after Haley, attacking her as "corrupt" and "fascist" for making money on speeches and serving on the board of Boeing.

"I love all the attention, fellas," she said, before defending her work with Boeing and suggesting her rivals were jealous she had the backing of major donors.

Ramaswamy, a staunch isolationist, was alone in arguing the U.S. should end its support for Ukraine against Russia. He took aim at Haley, who has emphasized her foreign policy credentials, saying that experience "is not the same as wisdom."

In response, Christie defended Haley, telling Ramaswamy he was coming across as "the most obnoxious blowhard in America."

Meanwhile, Haley, who called Ramaswamy "scum" at the last debate, said it was "not worth my time to respond" after he again called her corrupt.

Ramaswamy also advanced a number of baseless conspiracy theories, claiming the Jan. 6, 2021, assault on the U.S. Capitol by Trump supporters was an "inside job" and that the 2020 election was stolen.

(Reporting by Gram Slattery; Additional reporting by Costas Pitas, Eric Beech and Caitlin Webber; Writing by Joseph Ax; Editing by Ross Colvin and Daniel Wallis)