President Trump regularly criticizes his critics. He has called Joe Biden “sleepy” and Sen. Bernie Sanders “crazy.” But he seems to save some of his most personal attacks for women and, specifically, women of color, such as Sen. Kamala D. Harris.

Harris (D-Calif.), who is running for the Democratic presidential nomination, attracted attention Wednesday during Attorney General William P. Barr’s testimony. The Washington Post’s Jacqueline Alemany wrote that Harris, a former California attorney general, offered up “sharp, concise and repeated” questions that generated some news. She got Barr to acknowledge, for example, that he had not reviewed the underlying evidence in special counsel Robert S. Mueller III’s investigation before deciding not to charge Trump with obstruction of justice.

More than 2 million people watched a clip of Harris’s questioning on Twitter, and her team used it in a fundraising push Wednesday night.

So perhaps it’s not surprising that Trump soon weighed in on the senator’s performance. In an appearance on Fox Business Network, he told host Trish Regan that Harris had been “probably very nasty” to Barr.

Trump then expanded his comment to include the other Democratic presidential contenders on the panel, Sens. Cory Booker (N.J.) and Amy Klobuchar (Minn.). “You have three of them running against me, and they were up there ranting and raving like lunatics, frankly,” Trump said. “How is that fair?”

But Harris was the only person he attacked by name.

It’s not the first time he has referred to the candidate, who is polling at 4 percent among Democrats in the most recent Post-ABC survey, as “nasty.” While speaking to Fox News’s Sean Hannity last week, Trump said Harris has “a little bit of a nasty wit, but that might be it.”

By calling Harris “nasty,” Trump seems to be drawing on troubling and pernicious stereotypes that paint black women as “angry.”

“Black women are not supposed to push back, and when they do, they’re deemed to be domineering, aggressive, threatening, loud,” Trina Jones, who has studied racial stereotyping and how it plays into the lives of African American women, told the BBC.

And as I wrote previously, Trump has a long history of directing his harshest attacks toward black women, a group that has been critical of him since the earliest days of his administration. He has targeted Rep. Maxine Waters (D-Calif.), White House correspondent April Ryan, media maven Oprah Winfrey, former ESPN anchor Jemele Hill, former national security adviser Susan E. Rice and former Democratic National Committee chairwoman Donna Brazile.

He called Rep. Frederica S. Wilson (D-Fla.) “wacky” and dishonest, and he tweeted that Omarosa Manigault Newman, once the highest-ranking black woman in his administration, was a “crazed, crying lowlife” and a “dog.”

Harris is the only black woman running for president, and her supporters say she faces unique challenges that make it harder to get media attention and raise funds. With his “nasty” descriptor, Trump is mining some of the same stereotypes that make it hard for black women to succeed in politics. It’s a classic Trump tactic.