Trump must expect Jeb to find his dehumanization of illegal immigrants repulsive. But like any good bully, he can smell fear. He knows that Jeb, like most of the other Republican presidential candidates, fears the animal spirits he has awoken inside the GOP base. And so he’s virtually dared Jeb to double down on what he really believes. Asked this week about Jeb’s trip to a town near the Mexican border, Trump quipped that “he’ll now find out that it is not an act of love … I think he’ll probably be able to figure that out, maybe.”

It was a test: not of Jeb’s views on immigration, but of his character. A test of whether, when challenged on a subject close to his heart, the former Florida governor can show “energy.” Whether he can show he really is a “warrior.”

Jeb failed, badly. On the surface, he answered Trump’s attack. But it wasn’t really him answering; it was his political consultants. The week before, Jeb’s campaign had launched a new strategy aimed at exposing Trump as a fake conservative. Reading from his new script, Jeb told a New Hampshire crowd that, “Mr. Trump doesn’t have a conservative record. He was a Democrat longer in the last decade than he was a Republican.”

Team Jeb’s logic was clear and safe: Don’t attack Trump from the left, and thus alienate conservatives. Attack Trump from the right and thus win them over. So in response to Trump’s immigration dare, Jeb called the real-estate mogul’s immigration proposals … too expensive. “Mr. Trump’s plans,” Jeb declared on his trip near the border, “are not grounded in conservative principles. His proposal is unrealistic. It would cost hundreds of billions of dollars. It will violate people’s civil liberties. It will create friction with our third-largest trading partner that’s not necessary.”

It was the equivalent of the moment in 1988 when CNN anchor Bernard Shaw asked Michael Dukakis whether he’d support the death penalty if his wife were raped and murdered and Dukakis replied by citing statistics about the Massachusetts crime rate. Shaw wasn’t probing Dukakis’ views; he was probing his emotions. And Dukakis didn’t show any.

This week near the border, Bush did the same thing. The problem with Trump’s ideas about Mexican American illegal immigrants isn’t that they’re “unrealistic” or “expensive” or “not conservative,” whatever that means. It’s that they’re despicable. Trump, who lives to feed his ego, has realized that running for president can be the biggest ego-boost of all. He’s also realized that in today’s Republican Party, there are millions of downwardly mobile white Americans who are terrified about their economic prospects and alienated by America’s increasingly brown and black complexion. And he’s realized that by trashing the poorest of America’s poor, the exploited, undocumented immigrants who cross the border to do the brutal work upon which America’s economy relies, he can launch himself to the top of the presidential heap.