During his interview before the National Association of Black Journalists this week, Donald Trump was asked if he would call upon his fellow Republicans to refrain from labeling Vice President Kamala Harris a “D.E.I. candidate” for the presidency. Rather than condemn his party’s increasingly troubling language on the topic, Mr. Trump took the opportunity to question Ms. Harris’s racial identity.

“She was always of Indian heritage, and she was only promoting Indian heritage,” he said. “I didn’t know she was Black, until a number of years ago, when she happened to turn Black, and now she wants to be known as Black. So I don’t know, is she Indian or is she Black? I respect either one, but she obviously doesn’t.”

This is all clearly untrue. Ms. Harris graduated from Howard University, a historically Black university, and she is a member of Alpha Kappa Alpha, a historically Black sorority. Her biographies and self-descriptions throughout her career have cited both her Black and Indian identities.

My wife is white, so we have multiracial children. Depending on the context, they can refer to themselves as Black or multiracial. When my children describe themselves using the latter term, they are acknowledging that their mother is a part of their story as well. Does Mr. Trump really expect interracial people to deny half of their families?

But the lived experience of interracial families was probably far from his concern. His comments seemed designed to convince African Americans that Ms. Harris is not authentically Black, and, therefore, African Americans should not vote for her. This move also suggests to Indian Americans that Ms. Harris has abandoned her Asian identity, and so they should not support her either.

When Mr. Trump went on to suggest that “somebody should look into” Ms. Harris’s supposed shift in identity, he seemed to be prompting the two groups to claim her as solely their own, encouraging division.