Citing “specific threats to booksellers and the author,” Flatiron Books has canceled the remaining publicity tour for Jeanine Cummins’ “American Dirt” — replacing the usual events with town halls where the author will meet with allies of the threat-makers.

How very sad.

Tapped by Oprah Winfrey for her book club, the novel is about a Mexican mother and son fleeing violence to the United States.

The threat-makers’ central gripe: Cummins herself isn’t Mexican, indeed “only” has one Puerto Rican grandparent. And while her husband immigrated illegally, he’s from Ireland.

All of which supposedly limits what Cummins can write about. What a cramped view of human imagination and empathy.

Some critics complain that the publishing industry would rather support and publish a white writer rather than a Latino or Latina writer. But book publishing may be the most PC industry outside of academia — witness Flatiron’s pathetic retreat.

These idiots are now pressing Oprah to reconsider her book club pick, and to start featuring more works by “Latinx” (a ridiculous word) and immigrant authors. She’s not caving — except that she now plans to host all sides in an episode of her “Oprah’s Book Club” show. That’s sad, too — though it will give the critics a chance to prove how unhinged they really are.

Meanwhile, “American Dirt” is No. 1 on Amazon, so justice isn’t dead.