Trump wants Warren to prove her Native American heritage.

Native American leaders have said the "Pocahontas" nickname is culturally insensitive and racist. Warren herself called it a slur.

Would a DNA test prove her claims?

Probably not, and Warren said on NBC News' "Meet the Press" in a March interview she will not take one.

DNA tests are not widely accepted as proof of tribal citizenship — in part because the DNA could not show a specific tribe, only some genetic markers from Native people — and are more unreliable for Native Americans than for large ancestral regions like Asia or Africa.

“The reality is she could take a DNA test and have Native ancestry and have it not show up because it depends on which branches of the family tree it’s in and how far back,” Smolenyak said. “That test is very good for finding stuff out going back five, six generations. If you have one great-great-great-great-grant-great grandmother, it’s not going to show.”