Later in the evening, the moderators asked about Trump’s proposal to ban Muslims from entering the United States. Christie and John Kasich said they disagreed. Jeb Bush disagreed at length. Rubio did not. Instead, he began his answer by praising Trump for having “tapped in to some of that anger that’s out there about this whole issue because this president has consistently underestimated the threat of ISIS.” Then, after talking about how awful ISIS is, Rubio declared that, “When I’m president. If we do not know who you are, and we do not know why you are coming when I am president, you are not getting into the United States of America.” The listener who didn’t already know Rubio’s position might well have thought he supports Trump’s plan.

This is the Florida senator’s new strategy. He doesn’t reject Trump’s bigotry; he piggybacks on it. When asked in late November about Trump’s call for closing mosques, Rubio said, “It’s not about closing down mosques. It’s about closing down any place—whether it’s a cafe, a diner, an Internet site—any place where radicals are being inspired.” In other words, Trump didn’t go far enough.

But Rubio’s worst moment came near the debate’s end, when Maria Bartiromo asked why the bill he cosponsored in the Senate would have distributed 10 million new green cards over 10 years. For years now, the Ann Coulter wing of the Republican Party has been pillorying Rubio for having supported a path to citizenship for undocumented immigrants. But Bartiromo’s question wasn’t about that. It was about legal immigration, the virtues of which Rubio has made central to his political being. When profiled on the cover of Time in 2013, Rubio let it be known that his mother had told him in Spanish, “Don’t mess with the immigrants, my son...They’re human beings just like us, and they came for the same reasons we came. To work. To improve their lives. So please, don’t mess with them.”

But the people Rubio needs to win don’t only dislike undocumented immigration. They dislike any immigration that involves swarthy faces and Spanish accents. In her proudly racist book, Adios America, from which Trump borrowed the material about Mexicans and rape, Coulter warns repeatedly about the “browning” and “shortening” of America. According to a Pew Research Center poll in September, 71 percent of Republicans think immigrants increase crime and 81 percent say immigrants don’t assimilate.

So instead of defending his past support of legal immigration, Rubio abandoned it. “The issue is a dramatically different issue than it was 24 months ago,” he began. “Twenty-four months ago, 36 months ago, you did not have a group of radical crazies named ISIS...The entire system of legal immigration must now be reexamined for security first and foremost.” Rubio didn’t explain what exactly that means but the implication is that because of ISIS, he would be far stingier about who can legally enter the United States. Back in 2013, when nativist Iowa Congressman Steve King tried to use the Boston marathon bombing as a pretext to limit legal immigration, Rubio responded that, “We should really be very cautious about using language that links these two things in any way.” Not anymore. Now Rubio is worried that the women and children fleeing rape and murder in Guatemala are trying to establish a caliphate in Southern California.