Morry Gash / AP

The confrontation between Donald Trump and John Kasich in Tuesday night’s Republican debate over immigration was telling—not because they shared practical solutions, but for what it revealed about how each views the country and its ideals.

The debate laid bare clear divisions among the party’s presidential candidates on the hot-button issue. Trump fielded a question on immigration, and offered a response that he has regurgitated several times on the campaign trail—and which accounts for his surge in the polls.

“We are a country of laws. We need borders,” Trump said. “We will have a wall. The wall will be built. The wall will be successful.” It’s a regular talking point for the real-estate mogul, who also vows that Mexico will pay for the wall. But, on Tuesday, it was his deportation strategy that drew the strongest response from his rivals. Trump has said that he would deport 11 million undocumented immigrants in one fell swoop. Ohio Governor John Kasich dismissed that idea as a “silly argument.”

Instead, Kasich invoked the emotional burden such a move would impose on the families of undocumented immigrants. “Think about the families, think about the children,” he said, adding, “if they’ve been law abiding [and] they pay a penalty, they get to stay.” The Ohio governor has described the immigrant community in a similar frame before. “They’re hard workers, they’re God-fearing, they’re family-oriented,” he told CNN. “If they committed a crime, they’ve got to be deported or put in prison, but the only reason I say that is we have to solve this.”

But on Tuesday night, Kasich failed to provide an alternative approach to immigration reform. (Kasich hasn’t dismissed a possible pathway to citizenship for undocumented immigrants in the U.S. in the past, but neither did he advocate that step on Tuesday.)

This wasn’t simply a policy dispute, but a fight over premises. In his remarks, Trump implied that being an American is a privilege, not a right. His argument against undocumented immigrants implicitly rejects the notion that the U.S. benefits from such immigration, or is morally committed to offering opportunity. As Charles Kenny recently noted:

Emma Lazarus’s sonnet engraved on the base of the Statue of Liberty echoed a belief held ever since then: that the idea of America is wrapped up in the welcoming of huddled masses through its golden door, so that they can live in a better life.

But Trump’s argument connects to the Republican base by successfully tapping into a very different ideology. Republican voters have taken to the far right on the issue, fueling Trump’s campaign. Ted Cruz has taken note, and is using a similar approach to solidify his position with core voters, who have been backing outsider candidates like Trump and Ben Carson. Trump has drawn the support of such voters perhaps because he believes that illegal immigration poses a threat to the United States, and vows to protect the country and uphold the law.

Meanwhile, Kasich’s approach to immigration rests on a different set of principles. In his remarks, he stressed the pain deportation would inflict on families, which could be torn apart. His opposition to Trump’s scheme was framed as humane and pragmatic.

Jeb Bush, by contrast, appealed to principle. The former Florida governor has supported a pathway to citizenship and, on many occasions, worked to appeal to Hispanic voters, either by speaking Spanish or citing his ties to the community through his family. So it comes as no surprise that when pressed on immigration he would offer a principled response: Sending millions of people back to Mexico is “not embracing American values.”

“It would tear communities apart. And it would send the signal that we’re not the kind of country that I know America is,” Bush said.

Even as Kasich and Bush swung at Trump’s ideas about immigration, there was little effort to outline viable alternatives. Would they tackle immigration reform if elected president? What policies would they enact instead? The same holds true for Ted Cruz, who also jumped into the debate.

In contrast to Bush’s concern for values, or Kasich’s attention to families, Cruz placed his own emphasis on the interests of two other groups: American workers, and aspiring immigrants. “If Republicans join Democrats as the party of amnesty, we will lose,” Cruz said. “Every sovereign nation secures its borders, and it is not compassionate to say we’re not going to enforce the laws and we’re going to drive down the wages for millions of hard-working men and women.”

Cruz has long opposed a pathway to citizenship. In 2013 he told ABC, “I think a path to citizenship for those who are here illegally is profoundly unfair to the millions of legal immigrants who followed the rules.” Two years later, there was no mention of policy to address immigration in the U.S. (Cruz was also the first candidate to side with Trump on the issue—perhaps, in part, because he’s trying to pick up Trump’s supporters should he drop out of the race.)

The polls suggest that, among the Republican primary electorate, Trump and Cruz are winning their argument with the likes of Kasich and Bush. But among the public at large, it’s a more complicated picture. Other candidates, Marco Rubio most notable among them, avoided taking clear stands on Tuesday. But as the race moves on, they, too, will be called upon to articulate their own principles for tackling immigration, and to explain how they would put them into practice.

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