New York Times columnist Paul Krugman argued Thursday evening that President Donald Trump's rhetoric and policies toward immigrants mirror some of the darkest elements of historical anti-Semitism.

"What’s almost equally remarkable about this plunge into barbarism is that it’s not a response to any actual problem," he writes in a column titled "Return of the Blood Libel." "The mass influx of murderers and rapists that Trump talks about, the wave of crime committed by immigrants here (and, in his mind, refugees in Germany), are things that simply aren’t happening. They’re just sick fantasies being used to justify real atrocities."

He continued: "And you know what this reminds me of? The history of anti-Semitism, a tale of prejudice fueled by myths and hoaxes that ended in genocide."

Krugman goes on to note that while there are some minor debates about the effects of immigration on segments of the labor markets, there's no credible argument that immigration is anything like the scourge that Trump envisions it to be — in fact, it's believed to be broadly beneficial. Crime remains near record lows in the United States, and the places that have the most immigrants have less crime.

Meanwhile, most of the anti-immigrant animus in the country comes from the corners with the fewest immigrants.

In this way, there are disturbing similarities to the patterns of anti-Semitism.

"The thing about anti-Semitism is that it was never about anything Jews actually did," Krugman writes. "It was always about lurid myths, often based on deliberate fabrications, that were systematically spread to engender hatred."

Bizarrely, one of the most persistent anti-Semitic myths of a Zionist plan for world domination, Krugman notes, may have been concocted by — who else? — Russian secret police.

He concludes:

In any case, the important thing to understand is that the atrocities our nation is now committing at the border don’t represent an overreaction or poorly implemented response to some actual problem that needs solving. There is no immigration crisis; there is no crisis of immigrant crime. No, the real crisis is an upsurge in hatred — unreasoning hatred that bears no relationship to anything the victims have done. And anyone making excuses for that hatred — who tries, for example, to turn it into a “both sides” story — is, in effect, an apologist for crimes against humanity.

It's worth reading the whole column. Some have pushed back against the comparisons between Nazis and the cruel actions of the Trump administration, but Krugman shows how the analogy can be drawn clearly and responsibly.

No, the camps that the Trump administration are housing immigrants children in are nowhere near as bad as German concentration camps. But Krugman demonstrates how our times may be analogous to events and historical patterns that led up to the atrocities of the Nazi-era, as well as other atrocities. And there's nothing wrong with warning that social trends may be heading in an authoritarian, dictatorial, or genocidal direction — that may be the best way to prevent the worst outcomes from ever recurring.