Charles Krupa/AP
Opinion writer

In a better world, after each presidential campaign, the news media would examine the weaknesses of its coverage and resolve not to repeat its mistakes. Alas, that is not the world we live in.

After outlets devoted thousands of column inches and hours on TV news to the vital issue of whether Hillary Clinton used the wrong email, there are signs it could happen all over again. I refer you to this article in Thursday’s New York Times about Elizabeth Warren, which examines the fallout from Warren’s decision to take a DNA test to see if, as she was told growing up by her parents and other relatives, she had some Native American ancestry:

But nearly two months after Ms. Warren released the test results and drew hostile reactions from prominent tribal leaders, the lingering cloud over her likely presidential campaign has only darkened. Conservatives have continued to ridicule her. More worrisome to supporters of Ms. Warren’s presidential ambitions, she has yet to allay criticism from grass-roots progressive groups, liberal political operatives and other potential 2020 allies who complain that she put too much emphasis on the controversial field of racial science — and, in doing so, played into Mr. Trump’s hands.

Advisers close to Ms. Warren say she has privately expressed concern that she may have damaged her relationships to Native American groups and her own standing with progressive activists, particularly those who are racial minorities. Several outside advisers are even more worried: They say they believe a plan should be made to repair that damage, possibly including a strong statement of apology.

Welcome to “But her emails!”, version 2020.

Even if you think Warren shouldn’t have bothered with the DNA test, answer this question: So what? I mean actually answer it. See if you can complete this sentence without sounding ridiculous: Elizabeth Warren’s DNA test is extremely important to the question of what sort of president she would be and deserves endless discussion because ___.

To be clear, I’m not arguing that we must never speak of this again. But when we do, it should be with the understanding, and the explicit discussion, of the fact that this is both utterly disconnected from anything having to do with the presidency and something Republicans will try to use to distract from anything resembling a real issue.

Coverage such as this that fails to acknowledge those facts is doing President Trump’s work for him. And I know there are liberals now saying, “I used to love Warren, but after that DNA thing, I don’t know . .. “t I would argue that their doubts are the result of this coverage, not the cause of it. It’s all too reminiscent of 2016.

I’m also not trying to persuade anyone to support Warren in 2020. She has a lot to commend her as a candidate, but so do many of the other Democrats who will run; there will be no shortage of attractive options for any liberal to choose from. At this point I remain staunchly agnostic on the question of whom the party should nominate. But it is positively bonkers that this is going to be treated as an important “issue.”

Just as bonkers as it was that so much time and attention was devoted to Hillary Clinton’s emails, as though that was really what mattered in 2016. But just as with Clinton and the emails, we’re going to see this trivial matter be elevated to the most important thing we have to talk about when we talk about Warren, through a cooperative effort between Republicans and the news media. The latter will say endlessly that it “raises questions” about Warren while seldom specifying what those questions are, because the questions are so stupid. Questions such as, “Can someone who got criticized for taking a DNA test find a way to address climate change?”, or “If Warren made a PR misstep with this DNA test, does that mean she won’t be able to assemble congressional coalitions to pass major legislation?”

But PR missteps are always the news media’s justification for making mountains out of the tiniest molehills, a way of distancing reporters from their own judgments. (“Questions are being raised,” after all.) Warren will be blamed relentlessly not only for the disingenuous criticism of Republicans but also for the very fact that reporters will keep asking her about this just as they kept asking Clinton about her emails, an endlessly recursive cycle of coverage and condemnation.

That this will play out against the backdrop of the most corrupt presidency in our lifetimes, presided over by a candidate whose copious and highly relevant character flaws were addressed only superficially in 2016, makes it all the more appalling. For instance, the New York Times reported two months ago in an exhaustively documented investigation that the president and his family engaged in a years-long conspiracy to commit tax fraud on an absolutely epic scale, to the tune of hundreds of millions of dollars. What happened after that story broke? The president doesn’t get asked about it. There have been no follow-up investigations by other news organizations. When I brought it up, you probably said, “Oh yeah, I forgot all about that.” That’s because no one in the media talks about it anymore. It fell down the memory hole.

But that will never happen to Elizabeth Warren’s DNA test, which will be hashed and rehashed and re-rehashed every day of her candidacy. We will never be allowed to stop thinking about it, and voters will be convinced that it is absolutely essential to the question of whether Warren would be a good president.

Trump would like to keep this issue central to Warren’s candidacy because (as I’ve explained) it’s a kind of white racial resentment bank shot. But the rest of us, including those in the news media, have a choice to make it about what we think is important. We can decide to rerun “But her emails!” all over again in 2020. Or we can try to learn from the mistakes of the past.