This is what we’ve come to.

The publisher of a novel titled “American Dirt,” by Jeanine Cummins, has canceled the remainder of a national book tour because Cummins and the bookstores set to host her have received threats of physical violence.

This is what we’ve come to. In the United States of America.

More than 30 years after the Ayatollah Khomeini issued a fatwa demanding the assassination of Salman Rushdie for writing “The Satanic Verses,” here we are terrorizing one of our own novelists.

If you’ve been distracted lately by the presidential impeachment trial, you may have missed this tertiary symptom of the collapse of our democracy.

“American Dirt” was published last week in a paroxysm of rage and praise that racked the literati and generated almost 50,000 hardcover sales in its first five days.

Cummins’s novel tells the story of a Mexican bookstore owner named Lydia and her 8-year-old son trying to escape a poem-writing drug lord. The novel opens with his men killing 16 members of Lydia’s family during a quinceañera, and now they want to finish the job. With gunshots ringing in their ears, Lydia and her boy flee. They sneak onto buses, they jump onto moving trains, they trudge across deadly deserts, hoping against hope to reach the promised land: America.

It’s just a melodramatic thriller tarted up with flowery ornaments and freighted with earnest political relevance. The book might have fallen unremarked into the great vat of sentimental suspense fiction that New York pumps out every year, except for an unprecedented collision of promotion and denunciation.

Early on, the publisher, Flatiron, a division of Macmillan, decided to aim for the stars. It reportedly paid more than a million dollars for “American Dirt,” which isn’t so much an estimate of its value as an investment in the future publicity that such an absurd advance inevitably generates in Places That Matter. Flatiron determined that “American Dirt” would not just be another thriller; it would be the defining novel of the immigrant experience — an emotional story powerful enough to galvanize the sympathy of a nation. An Olympian field of blurbers was assembled, including John Grisham, Stephen King, Ann Patchett, Julia Alvarez and Sandra Cisneros. Don Winslow called it “a ‘Grapes of Wrath’ for our time,” which is ludicrous but hardly out of bounds in the make-believe realm of blurbs. Movie rights were sold. Barnes & Noble picked it for the chain’s national book club. And finally, Oprah announced that “American Dirt” was her next book club pick.

But more than a month ago, long before most of us had heard of this book, Chicana writer Myriam Gurba posted a take-no-prisoners review on a website titled Tropics of Meta. Gurba exposed the novel’s cliches, stereotypes and clumsiness, and then she went after Cummins for appropriating the story of Mexican migrants and exploiting their suffering. It’s a fierce critique, full of insight and anger — the kind of urgency one almost never sees in the pages of the nation’s hand-patting book reviews. Other writers noticed — particularly people of color — and by the time the novel was released on Jan. 21, the Internet was full of smart commentary that not only delineated the flaws in “American Dirt” but also the deleterious effects of baking mawkish racial stereotypes in sweet nuggets for a largely white, ill-informed audience. Other commentators pointed out the problems in a publishing community that could so enthusiastically promote such a flawed novel. And some writers helpfully suggested better novels and works of nonfiction about migrants and the border crisis.

That’s how the cultural system is supposed to work. It was heartening to see people so engaged with a work of fiction. But the cruel design of our attention-based economy means that we end up promoting loudest what we hate most.

And in the current climate, hate quickly becomes weaponized. Gurba told Vox this week that she had received death threats after posting her review of “American Dirt.” And the ad hominem comments about Cummins flying around the Web have been brutal. From the start, too much of the discussion of this mediocre novel has been snarled up in identity politics — a poisonous tendency encouraged by the author herself. In a pleading afterword to “American Dirt,” Cummins confesses that she wished “someone slightly browner than me would write it.”

Cummins has been attacked for exaggerating her ethnic background and for failing to note that her Irish husband — once an illegal immigrant — didn’t belong to a sufficiently repressed minority group. (That complaint is so clouded by historical amnesia that I don’t know where to start.) Listening to the anger directed at Cummins for having only one Latina grandparent, I suppose future novelists will have to submit their manuscripts along with a 23andMe genetic profile.

More than 120 prominent writers — many of whom I idolize — signed a petition this week asking Oprah to cancel her book club selection because, they write, “American Dirt” “has not been imagined well nor responsibly, nor has it been effectively researched.” Such judgments on this novel have and should be made, but now, to read “American Dirt” or even to tolerate others reading it is to risk being regarded as a participant in its “harmful” effect.

I heard Cummins speak at a Politics and Prose bookstore last week. The friendly, standing-room-only audience included her old neighbors, friends, teachers and even the mayor of Gaithersburg, Md., where she was raised. Cummins began by saying, sometimes through tears, that her father died while she was working on “American Dirt,” and the relationship between her protagonists reflects the love between her and her dad. She went on to explain that the trauma described in the novel was informed by the pain her brother suffered during a horrific crime in St. Louis that almost killed him and left her two cousins gang raped and murdered.

Although she claimed not to have read the negative critiques of “American Dirt,” she was clearly cognizant of the complaints — and she wasn’t timid about pushing back. “I did five years of research,” she said. “I went to the border. I went to Mexico. I traveled throughout the borderlands. I visited Casa del Migrante in Mexico. I visited orphanages. I volunteered at a desayunador, which is like a soup kitchen for migrants. I met with the people who have devoted their lives on the front line to the work of protecting vulnerable people. . . . And despite the fact that it has grown into this crazy moment that I never anticipated and that feels as if I’m in the eye of the hurricane, I know for a fact that this book is moving people.”

It’s worth recalling an earlier melodramatic thriller tarted up with flowery ornaments and freighted with earnest political relevance by a white woman named Harriet Beecher Stowe. We can debate how egregiously Stowe appropriated the lives of black people and exploited their suffering, but President Abraham Lincoln said that “Uncle Tom’s Cabin” sparked the Civil War. If “American Dirt” similarly motivates some Americans to fight against this country’s immoral immigration actions along the southern border, then more power to Cummins. And once engaged in that struggle, these readers might move on to better books.

But some detractors are determined to short-circuit such a possibility — or any discussion sparked by this novel. Fortunately, Flatiron remains committed to serious debate. Although Cummins’s bookstore tour has been canceled, the publisher has announced plans to conduct town hall meetings involving Cummins and “some of the groups who have raised objections to the book.” Let’s hope those discussions can move forward without bullying, intimidation or violence.

The co-owner of Politics and Prose, Lissa Muscatine, articulated that goal when she introduced Cummins last week. She noted that “American Dirt” raises questions such as: “Who is entitled to tell whose story? What is the purpose of literary fiction? Does a white-dominated publishing world perpetuate cultural bias in its choices of authors and books to promote?” Before turning over the microphone to Cummins, she reminded us, “Here at P and P, our only requirement is that we all remain respectful and generous as we listen to and hear from one another, even when we disagree.”

How grotesquely that modest requirement of liberal society has been soiled this week. And we can’t blame the threats against Cummins on President Trump’s race-baiting rhetoric or his obscene immigration abuses. The best critics of “American Dirt” are clearly motivated by a desire to defend the integrity of Mexican culture and the humanity of our most vulnerable residents. But in today’s toxic atmosphere, those valuable critiques have been drowned out by a cowardly chorus of violence.

This is what we’ve come to. And it’s terrifying.

Ron Charles writes about books for The Washington Post and hosts TotallyHipVideoBookReview.com.