DES MOINES — Four days until Iowa kicks off voting of the 2016 cycle, Republican candidates for president had one last chance to convince voters why caucusgoers should turn out for them Monday night.

Ted Cruz, Marco Rubio, Ben Carson, Jeb Bush, Chris Christie, John Kasich and Rand Paul participated in the event. Donald Trump was missing — who decided to skip out on the debate.

Here are five takeaways from the event, which ran two hours on Fox News Channel from the Iowa Events Center in downtown Des Moines.

1. Trump absent from debate

“The elephant not in the room,” as moderator Megyn Kelly put it, was front-runner Donald Trump skipping the debate. Trump, accusing Kelly of being “biased against him,” opted to skip out on the final debate before voting and hosted an event about 10 minutes away at Drake University in Des Moines.

Fox issued a statement shortly before the debate saying Trump did offer to appear at the event, but only if the network would donate $5 million to charities — which they refused to do.

Cruz was asked from the start about Trump’s absence, but he instead, as a joke, lobbed insults at the other candidates and said the “Donald Trump portion” of the debate is over.

“Let me say this: I’m a maniac, and everyone on this stage is stupid, fat and ugly, and Ben, you’re a terrible surgeon,” Cruz joked.

 He added that he still does not plan to reciprocate and personal attacks from Trump and campaign.

Bush also joked, saying he and Trump have “always had a loving relationship.”

Carson was the only candidate on stage without any political experience, which he said he was glad to talk about.

“We need people who think outside of the box and can solve problems,” Carson said.

2. Rubio and Cruz called out on immigration

Before a commercial break, Fox teased “something you’ve never seen before” on immigration, then played several soundbites from Rubio talking about the issue. Several past clips showed Rubio saying an “earned pathway to citizenship” is code for “amnesty,” which Rubio says he does not support now.

Rubio co-sponsored a bill in the Senate that would offer a pathway to citizenship, but Rubio later backed off.

At the debate, Rubio argued that the language and timing was important. He pointed to a bill in the Senate that he said was “amnesty” in 2009, but his bill was tougher.

Bush went after Rubio — the two have gone after each other throughout the campaign after being friends from Florida — saying he clearly switched his position because it “was not popular.”

3. Establishment candidates try to stand out

Candidates who were well funded throughout the campaign have struggled to gain traction they would see during any other election cycle.

Bush seemed to embrace the establishment label, if it means that he is connected to the Bush family.

Later in the debate, Bush was asked about his campaign running negative ads against other Republicans when polls show him not being able to beat Hillary Clinton if he is the nominee. Bush responded by saying he has no control over Super PACs, but his record is enough to show that he can beat Clinton.

Christie said even as an “establishment” candidate, he is a conservative who got things done in New Jersey. He also called on senators on the stage — as he has done throughout the campaign — saying they have not actually accomplished anything in Washington.

Kasich chimed in at several points about foreign policy and also made a plea for the United States to get to work on mental health issues.

4. Rand Paul asked about liberty vote

Rand Paul was widely expected to follow in the footsteps of his father, former U.S. Rep. Ron Paul, R-Texas; instead, his campaign has been flanked by low polling as Cruz and Trump have led the race.

Paul was asked if he regrets not embracing his father’s brand of libertarianism and why he thinks libertarian-leaning-Republicans have decided to back a candidate like Cruz. He responded by pivoting to a Senate vote earlier this month of Audit the Federal Reserve, which failed in the Senate, and added that he does not think liberty voters will flock to Cruz because he missed the vote.

He also mentioned his fight to reform the NSA’s bulk collection and his less aggressive foreign policy, which Rubio and Christie argued has made America less safe. 

Rubio also went after Cruz for voting in favor of Paul’s balanced budget proposal in the U.S. Senate, which would make drastic cuts across the board — including military spending.

“You can’t destroy ISIS with a military that is being diminished,” Rubio said.

5. Four candidates try to stand out in early debate

Four other candidates were on stage for the “undercard” debate earlier in the evening, quickly coming out swinging about Trump and how they feel it is unfair treatment from the media during this election cycle.

Rick Santorum, who won the caucus in 2012, was visibly upset when moderator Bill Hemmer asked him if Monday would be the last day of his campaign.

Instead of answering, he blasted the moderators for the coverage leading up to the first debate — which focused mostly on how Trump decided to skip the debate.

“[The first debate] wasn’t advertised significantly,” Santorum said. “In fact, the entire hour leading up to this there was no conversation about any of the four people on this stage.”

Hemmer quickly pointed out that Santorum was set to appear later in the evening at Trump’s event — as was Huckabee — at Drake University.

“You know, this is more of the politics of trying to get people to throw stuff at each other,” Santorum said. “I’m not going to throw mud at anybody on this stage tonight.”

Santorum said he was invited by Trump to speak at his event, which would be raising money for veterans, so he was happy to appear.

Mike Huckabee was asked why his message was not “resonating” like it did in 2008, when he won the caucus. He responded that it is not a problem of it not resonating, instead all of the attention is on candidates like Trump.

Jim Gilmore, who has mostly been excluded from past debates because of low polling, was asked why he has not hosted any campaign events in Iowa. He responded by insisting it is a part of his strategy to spend his campaign time in New Hampshire.

Gilmore also called out Santorum and Huckabee for their plan to appear with Trump, saying he will not “go across town and carry the coat for some billionaire.”

Carly Fiorina also appeared at the early debate after being booted from the primetime event because of low polling.