DES MOINES, Iowa — A debate without Donald Trump offered his rivals a chance to escape his long shadow Thursday, resulting in sharp exchanges among Republicans hoping to survive the winnowing of the presidential field that will begin Monday in Iowa.

The billionaire real estate mogul’s spat with Fox News, the debate host — a fight that began months ago with harsh questions from debate moderator Megyn Kelly — produced an unusual political split screen as seven leading contenders shared a stage on one cable network and the national leader in the polls stood alone at his own competing event, being aired by another.

While Trump was not present, his name and influence on the field were mentioned from the start, as Kelly asked about the “elephant not in the room.”

Texas Sen. Ted Cruz opened with a series of insults at his rivals, joking that he was presenting the “Donald Trump portion” of the debate. Later, he gibed that if there were any more tough questions, he might have to walk off the stage.

Florida Sen. Marco Rubio called Trump the “greatest show on Earth” but insisted the election was about more important matters. And Jeb Bush, a frequent sparring partner of Trump in the last six meetings, said he missed the “teddy bear.”

“Everyone else was in the witness protection program when I went after him on behalf of what the Republican cause should be: conservative principles, belief in limited government, belief in accountability, leading by fixing the things that are broken,” Bush said.

But the forum quickly moved on and offered voters a glimpse at the primary-within-the-primary that has been playing out for weeks among the candidates not named Trump, particularly in an intense exchange over immigration policy that drew in Cruz, Rubio and Bush.

Confronted by Kelly with video of his statements in support of an amendment he had offered to a 2013 immigration reform proposal, Cruz insisted that he was not a proponent of so-called “amnesty.”

“We can build a fence, we can triple the border patrol, we can end sanctuary cities,” he said. “What is missing is the political will because too many Democrats, and sadly too many Republicans don’t want to solve this problem.”

Rubio pounced, calling Cruz’s claims about his conservatism the “lie” that his campaign is built on.

“The truth is, Ted, you’ve been willing to say or do anything to get votes,” he said.

Rubio faced his own video moment as Kelly showed clips of statements early in his career opposing any path to citizenship for those in the country illegally, juxtaposing them with the Senate immigration compromise he backed in 2013 that would have created such a pathway.

As Rubio tried to insist that his position was consistent, Bush accused him of misleading voters.

Then, as Cruz and Rubio continued to pummel each other, New Jersey Gov. Chris Christie jumped in to remind voters of one of his chief credentials — not being a member of Congress.

“Stop the Washington bull,” he said.

Earlier, Cruz and Sen. Rand Paul of Kentucky sniped over Senate votes on national defense and surveillance programs as they competed for the votes of tea party voters and libertarians.

The three past and present governors — Christie, Bush and John Kasich of Ohio — highlighted their records as executives in what has been called a fight for the “establishment lane.”

Rubio at times figured in both arguments, while also presenting himself as the best choice for Republicans eager to turn the page after eight years of President Barack Obama’s leadership.

“If I’m our nominee, I will unite this party and we’ll defeat Hillary Clinton and we will turn this country around once and for all,” he said.

Christie, too, made Clinton a frequent target, at one point talking about her to turn away a question about investigations into the “Bridgegate” scandal involving his former aides and their participation in a scheme that shut down a traffic lane at the George Washington Bridge.

“You know why the Republican Party will want to take a chance on me?” he asked. “Because they know that Hillary Clinton will never be prosecuted by this Justice Department, and they’re going to want to put a former federal prosecutor on the stage to prosecute her next September.”

For each of them, the spotlight glowed brighter because Trump, for months the center of gravity in the Republican nomination battle, had decided to boycot the proceedings, saying he was protesting Fox News Channel’s choice of Kelly as co-moderator and what he deemed to be an offensive and antagonistic comment by the network mocking his concerns about her fairness.

A Fox News spokesperson said network chairman Roger Ailes spoke briefly with Trump three times Thursday about possibly reconsidering. Trump offered to participate if the network donated $5 million to his charities, an offer the network rejected because it would have amounted to a quid pro quo, the spokesperson said.

Without him the crowd on stage, which also included retired neurosurgeon Ben Carson, was the smallest GOP gathering yet in the 2016 race. Earlier debates had as many as 11 candidates.

Trump’s presence in the race has produced an unpredictable and to an extent media-driven process. His rivals largely followed the traditional political playbook, campaigning aggressively in the early states while also raising significant sums of cash to support television advertising. Trump, by contrast, has been a regular presence on cable and network news shows — often simply via telephone — while holding large rallies across the country that have drawn thousands of supporters and curiosity-seekers alike.

With the real estate magnate-turned-reality show star as a draw, television ratings for the Republican debates have set records, often surpassing primetime network offerings. And Trump’s positions on issues like immigration and fighting terrorism have often set the agenda.

Monday night’s precinct caucuses will be the first true test of voter sentiments in the nominating process. Between the results here and those eight days later in New Hampshire, the sprawling GOP field likely will be culled to a significantly smaller number.

Four lesser-known candidates who faced off first in a preliminary debate, like Trump, made the political press a frequent foil.

Asked why his message wasn’t connecting in 2016 as it had in 2008, when he won the Iowa caucuses, former Arkansas Gov. Mike Huckabee responded that “the message isn’t getting out.”

The man who won the 2012 caucuses, former Sen. Rick Santorum, also objected to the media coverage.

“What Iowans deserve is to hear from every candidate on equal footing,” Santorum said after being asked if the state was his “last stand.”

Carly Fiorina, the former Hewlett Packard chief executive who has appeared in both undercard and main-stage debates this cycle, bemoaned Thursday what she called the “yawning chasm between what the national media talks about and what the people of Iowa and the people of this great nation talk about.”

And Jim Gilmore, the former governor of Virginia, making his first debate appearance after finally hitting 1 percent in a poll, complained that he would be doing better but for the way the media had covered the campaign.

Ultimately Huckabee and Santorum joined Trump for the event he organized opposite the debate at Drake University, which he said would raise money for wounded veterans.

The next Republican debate is set for Feb. 6, in Manchester, N.H., three days before that state holds the first-in-the-nation primary.