Donald Trump has just betrayed Ann Coulter. Which is a dangerous thing to do.

This week, Coulter released her new book, In Trump We Trust. As the title suggests, it’s a defense of Trump. But more than that, it’s a defense of Trumpism. Most Trump surrogates contort themselves to defend whatever The Donald says, no matter its ideological content. They’re like communist party functionaries. They get word from the ideologists on high, and regurgitate it as best they can.

Coulter is different. She’s an ideologist herself. She realized the potency of the immigration issue among conservatives before Trump did. On June 1 of last year, she released Adios America, which devotes six chapters to the subject of immigrants and rape. Two weeks later, Trump—having received an advanced copy—famously picked up the thread in his announcement speech.

Since then, they’ve been allies. But unlike many Trump defenders, Coulter makes clear that her primary allegiance is not to Trump the man. It’s to the nostalgic “Make America White Again” brand of conservatism that she began peddling even before he did. In In Trump We Trust, Coulter calls Trump a “tasteless, publicity-seeking, coarse billionaire” and argues that, “the one thing voters weren’t wild about was his personality.”

The secret of Trump’s success, she argues, has been ideological. He recognized that “Americans,” by which she mostly means Republicans, “are homesick.” They don’t just oppose immigration because they believe it depresses wages and strains government services. They’re homesick for a whiter America, an America that was once truly free because “it’s not in the Anglo-Saxon character either to take orders or to give them.” (Never mind about slavery.) Since 1965, however, when Lyndon Johnson signed legislation allowing more immigration from Latin America, Asia, and Africa, the United States has been, according to Coulter in In Trump We Trust, overrun by “illiterate peasants … who can be instructed to learn certain symbols and bloc-vote for the Democrats.” In response, Democrats, along with rich Republicans, keep the doors open to non-European immigration, and thus America has grown “browner” and “shorter.” (That’s Coulter’s description from Adios America). Corruption rises. So does terrorism and rape.

Coulter’s ideological interpretation of Trump’s appeal is plausible. It explains, for instance, why support for Trump correlates more strongly to racial resentment than economic misfortune.

Trump may win votes by moderating his stance on immigration. But that’s not how Coulter sells books.

Coulter’s problem is that on the very week she’s unveiled her immigration-themed defense of Trumpism, Trump himself has begun jettisoning it. On Wednesday night, he admitted that it’s “very, very hard” to deport all the undocumented immigrants in the country and implied that he would be open to some people being allowed to stay legally without becoming citizens, provided they pay back taxes. Suddenly, Trump is flirting with an immigration policy that resembles that of every other Republican who ran for president. Which makes Coulter look like a dupe. On Thursday on his show, Rush Limbaugh had a hearty laugh at her expense.

So far, Coulter has responded in contradictory ways. She’s fired off tweets attacking Trump’s immigration shift. But she’s also downplayed it.

Maybe Coulter, like the other high-profile supporters Trump has burned, will accept her humiliation and resort to defending Trump no matter what he says. Her incentives, however, are different. Unlike most of the folks who appear on television supporting Trump, she has an independent brand. And it’s built on white nationalism. Trump may win votes by moderating his stance on immigration. But that’s not how Coulter sells books.

Coulter also needs an explanation for Trump’s likely defeat, an explanation that will preserve her ability to claim that America’s silent majority believes the things she does. By emphasizing Trump’s immigration flip-flop, Coulter could argue that this issue cost him the white votes he needed to win.

Trumpism—a brand of conservatism defined above all by white racial nostalgia—will survive November’s election. Less clear is whether Trump will remain its champion or become its fall guy. Like many people Trump has done business with, Coulter has learned that trusting Trump is not the wisest of investments.