Don’t let them push you around, Sen. Warren. Please keep your spit to yourself.

Apparently, DNA tests are the new birth certificates. Because President Trump continues his immature taunting of Sen. Elizabeth Warren (D-Mass.) by referring to her as “Pocahontas,” his potential 2020 Democratic rival is being asked to take a test to determine whether she is, in fact, descended from Native Americans, as her family lore says.

“There are now so many commercial DNA heritage-tracking labs in business that they advertise on television,” the Berkshire Eagle of Pittsfield, Mass., suggested in an editorial last week. “The going rate for one of the most popular tests is $99. All the senator needs to do is spit into a tube, wait a few weeks and get her answer. No matter if the test came up negative or positive, it would constitute a plus for Warren and her political hopes.” Now, her unwillingness to take such a test is the talk of cable news.

But why should she? While no credible evidence supports that old story her parents told her, there is also no indication that her shaky claim to Native American ancestry ever benefited her, either during her earlier career in academia or in politics.

Warren handled it clumsily when the controversy erupted during her 2012 Senate campaign, but Massachusetts voters decided it did not matter. Now, there is but one reason it continues: Trump rarely misses an opportunity to take a dig at her, even doing it at a White House event honoring Navajo code talkers who were invaluable to the Marines during World War II.

Haven’t we been here before? Trump’s political rise was fueled in part by the fact that he was willing to purvey corrosive conspiracy theories. After President Barack Obama produced his birth certificate in 2011, it took Trump another five years to say he accepted that Obama was “born in the United States, period.”

Now, Trump is going even lower, to pre-birtherism.

Many of us grow up with stories that might not withstand some probing. In my own family’s case, there was a memento, a black-and-white photo of my grandfather dressed up in a doughboy uniform. I had the impression — I’m not really sure where it came from — that he had been gassed in World War I. He never contradicted it. Only after he died, when I found my grandfather’s military records, did I realize that he had not ever been overseas during the Great War.

The spotlight that comes with public life often produces surprising revelations about long-accepted family histories. Bill Clinton was president before he discovered he had an older half brother. 

It is possible Warren’s family story is wrong; it is possible there’s a kernel of truth that has gotten misplaced over time. But if so, it is ridiculous to turn such a common and understandable part of family life into a political attack.

Warren, to her credit, addressed the issue with grace in an appearance last month before the National Congress of American Indians.

“I get why some people think there’s hay to be made here. You won’t find my family members on any rolls, and I’m not enrolled in a tribe,” she said. “I respect that distinction. I understand that tribal membership is determined by tribes — and only by tribes.”

She added: “I’m here today to make a promise: Every time someone brings up my family’s story, I’m going to use it to lift up the story of your families and your communities.”

And, in the end, standing up to a bully will tell us more about what Elizabeth Warren is made of than any DNA test ever could.