DES MOINES — In the absence of Donald Trump, Republican presidential contenders turned their fire on Hillary Clinton, Barack Obama and the Democrats rather than each other.

The first primetime Republican presidential debate without the billionaire businessman featured more policy and fewer personal attacks as seven leading candidates made their closing arguments Thursday night, only days before the Iowa caucuses.

But that doesn't mean that the man Fox News co-moderator Megyn Kelly called the "elephant not in the room" was totally without impact on the event. His name was mentioned whenever one of the debaters wanted to go for some comic relief. And immigration, the issue has defined Trump's campaign, led to the most fireworks.

Marco Rubio accused Ted Cruz of trying to "out-Trump Trump" on immigration as he faced sharp questioning from Kelly about his own role in the 2013 "Gang of Eight" legislation, which featured a path to citizenship for illegal immigrants and increased legal immigration.

Rubio tried to argue there was no inconsistency between his firm opposition to amnesty during his 2010 Florida Senate race and his past support for a path for citizenship by claiming what he opposed was "blanket amnesty."

But Fox News produced video clips of Rubio describing even an earned path to citizenship for illegal immigrants as amnesty and said enacting one would undermine public confidence in legal immigration. Rubio reverted to the argument he had made in previous debates that the nature of the Islamic State changed everything, making keeping jihadists out of America the country's biggest immigration-policy priority.

Cruz wasn't let off the hook either. Kelly was just as tough asking him about his amendment to the "Gang of Eight" bill allowing a path to legalization, but not citizenship, for illegal immigrants. Fox showed video clips of the Texas senator appearing to argue for the amendment not as a "poison pill," a provision designed to kill the piece of legislation to which it is being added, but a good policy that would make the bill better and help it pass.

To which Cruz responded that if you don't believe his own claims to be Rubio's polar opposite on amnesty, ask immigration hawk lawmakers Sen. Jeff Sessions and Rep. Steve King (the latter an Iowan who has endorsed Cruz) or conservative radio talk show host Rush Limbaugh.

"When that battle was waged, my friend Sen. Rubio chose to stand with Barack Obama and Harry Reid and Chuck Schumer and support amnesty," Cruz said. "And I stood alongside Jeff Sessions and Steve King, and we led the fight against amnesty."

The immigration exchange highlighted several things that go beyond that particular issue. Rubio is making a push to join Cruz and Trump, the leading candidates in recent Iowa polling, among the top caucus contenders. Second, there were unusual alliances, with Jeb Bush accusing Rubio of having "cut and run" while admitting he had changed his position on a path to citizenship himself and Rand Paul joining Rubio in a tag-team effort against Cruz.

Bush is competing with Rubio, Chris Christie and John Kasich for establishment support. Rubio made a strong faith-based pitch to Iowans, suggesting that he isn't going to cede evangelicals to Cruz. And Paul is trying to prevent Cruz from purloining the libertarian base he inherited from his father.

Third, and perhaps most important, is that without Trump the Republican debate took a break from the "RINO hunting" that has dominated the 2016 race and many recent GOP primaries in down-ballot contests. ("RINO" is a popular conservative acronym for "Republican in name only.") Cruz was targeted by both Rubio and Paul for engaging in this practice, with the former calling it "the lie that Ted's campaign is built on."

"What is particularly insulting, though, is that he is the king of saying, 'You're for amnesty.' Everybody's for amnesty except for Ted Cruz," Paul said. "But it's a falseness, and that's an authenticity problem."

"This is the lie that Ted's campaign is built on, and Rand touched upon it — that he's the most conservative guy, and everyone else is a — you know, everyone else is a RINO," Rubio concurred.

Many of Rubio's best lines targeted the woman he says would be afraid to face him the general election, while he would relish the challenge. "Hillary Clinton's first act as president may well be to pardon herself," Rubio said, blasting her for housing sensitive government data on a private email server for convenience. Later, Rubio earned raucous applause by saying, "Hillary Clinton lied to the families of those killed in Benghazi."

Christie, a former U.S. attorney, also implied Clinton should be prosecuted and said he would ensure "she won't get within 10 miles of the White House." The New Jersey governor turned as many of his answers as possible into criticisms of Clinton, promising to end the Clintons' time in "public housing" and to make the case against her with the zeal of a prosecutor.

Paul argued Clinton's pose as a defender of women's rights is inconsistent with having a husband whose presidential conduct with an intern would have gotten him fired as a corporate CEO by many companies.

The tough questions from the moderators and the YouTube questioners' focus on diversity, tolerance and acceptance of immigrants lent credence to the argument that Trump bailed from the debate to avoid such an interrogation. Instead they were mostly directed at candidates like Bush and Rubio, who handled them in a conciliatory fashion.

Trump's absence also allowed Bush to turn in his strongest debate performance, partly because he wasn't being mocked as being low energy.

The final GOP debate before the Iowa caucus may not change the race as it is, but it did give voters a glimpse of what might have been.