Unlike the first GOP debate where presidential candidates raced to see who could go further to the right on immigration, the candidates at Wednesday's primary debate were forced to grapple with where the frontrunner Donald Trump has taken the divisive issue.
Trump found himself on the defensive because of his immigration plan that calls for deporting 11 to 12 million undocumented immigrants, which has been criticized as short on details and impossible.
New Jersey Gov. Chris Christie, who has flagged in the polls, said that deporting 15,000 immigrants a day would be impossible calling it "an undertaking that almost none of us could accomplish given the current levels of funding and the current number of law enforcement officers."
Christie advocated using drones and biometric fingerprints that would identify people who have overstayed their visas so they can leave the country.
As in the first debate, former Florida Gov. Jeb Bush was attacked by Trump for calling illegal immigration an "act of love" but this time responded forcefully, saying that he was on the side of Ronald Reagan, who believed in America's inclusive values. Bush contrasted that outlook with Trump, who he said believes everything happening in America is negative, including immigration.
Bush said the border must be secured, noting that he wrote a book on the subject, but chastised Trump for his plan.
"To build a wall and to deport people — half a million a month — would cost hundreds of billions of dollars, Donald. Hundreds of billions of dollars," Bush said. "It would destroy community life, it would tear families apart. And it would send a signal to the rest of the world that the United States values that are so important for our long-term success no longer matter in this country.
Florida Sen. Marco Rubio, asked if his plan was amnesty, said he supports building a border wall and instituting an entry/exit visa tracking system, at which point Americans "will be very reasonable and responsible about what you do with someone who's been here and isn't a criminal."
Neurosurgeon Ben Carson, who has risen to second in the polls, defended his plan calling for more guest workers as not being amnesty, repeatedly citing recent trips to the border. He said he spoke to farmers who said Americans won't take certain jobs in agriculture.
Trump once again invoked a San Francisco woman killed by an undocumented immigrant. He said immigration has become a major campaign issue because he brought it up, but this time former Hewlett-Packard CEO Carly Fiorina, who was not in the first debate, pushed back.
"Immigration did not come up in 2016 because Mr. Trump brought it up," she said. "We talked about it in 2012. We talked about it in 2008. We talked about it in 2004. We have been talking about it for 25 years."
Trump, who has said he would end birthright citizenship, said that "great" legal scholars believe the Constitution is being misinterpreted on the issue. He said Mexicans and Chinese immigrants come to the U.S. to have American citizen children.
"A woman gets pregnant. She's nine months, she walks across the border, she has the baby in the United States, and we take care of the baby for 85 years. I don't think so," Trump said.
Only Fiorina said Trump was off-base, "you can't just wave your hands and say 'the 14th Amendment is gonna go away,'" she said.
Bush and Rubio also double-teamed Trump for his criticism of candidates who speak Spanish on the trail.
Bush said that, if asked a question in Spanish by a high school student, "I'm going to show respect and answer that question in Spanish."
Rubio invoked his Cuban grandfather who taught him to love America, speaking to him in Spanish, and framed the choice to speak in another language as a way of sharing the message with Hispanics that "I believe that free enterprise and limited government is the best way to help people who are trying to achieve upward mobility."
He said doing so would be better than the alternative.
"And if they get their news in Spanish, I want them to hear that directly from me," Rubio said. "Not from a translator at Univision."
Bush also asked Trump to apologize for bringing up his Mexican-American wife on the trail and saying his immigration views are influenced by her. Trump and Bush interrupted each other, with Trump speaking positively of Bush's wife ("I hear phenomenal things. I hear your wife is a lovely woman.") but as usual refusing to apologize.
But while Trump was attacked throughout, he was defended by Ted Cruz who credited his candidacy with forcing the mainstream media to discuss illegal immigration.
For his part, Trump continued his approach of discussing complex issues in broad terms and few details.
"The great ones will come back, the good ones will come back," Trump said of the millions of undocumented immigrants he will send back to their countries through mass deportation. "They'll be expedited, they'll be back, they'll come back legally. We'll have a country -- they'll come back, legally."