First, a general point: Any claim that changed policy positions will win elections assumes that the public will hear about those positions. How is that supposed to happen, when most of the news media simply refuse to cover policy substance? Remember, over the course of the 2016 campaign, the three network news shows devoted a total of 35 minutes combined to policy issues — all policy issues. Meanwhile, they devoted 125 minutes to Mrs. Clinton’s emails.

Consider eastern Kentucky, a very white area which has benefited enormously from Obama-era initiatives. Take, in particular, the case of Clay County, which the Times declared a few years ago to be the hardest place in America to live. It’s still very hard, but at least most of its residents now have health insurance: Independent estimates say that the uninsured rate fell from 27 percent in 2013 to 10 percent in 2016. That’s the effect of the Affordable Care Act, which Mrs. Clinton promised to preserve and extend but Mr. Trump promised to kill.

Mr. Trump received 87 percent of Clay County’s vote.

Now, you might say that health insurance is one thing, but what people want are good jobs. Eastern Kentucky used to be coal country, and Mr. Trump, unlike Mrs. Clinton, promised to bring the coal jobs back. (So much for the idea that Democrats need a candidate who will stand up to the fossil fuels industry.) But it’s a nonsensical promise.

Where did Appalachia’s coal mining jobs go? They weren’t lost to unfair competition from China or Mexico. What happened instead was, first, a decades-long erosion as U.S. coal production shifted from underground mining to strip mining and mountaintop removal, which require many fewer workers: Coal employment peaked in 1979, fell rapidly during the Reagan years, and was down more than half by 2007. A further plunge came in recent years thanks to fracking. None of this is reversible.

You can’t explain the votes of places like Clay County as a response to disagreements about trade policy. The only way to make sense of what happened is to see the vote as an expression of, well, identity politics — some combination of white resentment at what voters see as favoritism toward nonwhites (even though it isn’t) and anger on the part of the less educated at liberal elites whom they imagine look down on them.

To be honest, I don’t fully understand this resentment. In particular, I don’t know why imagined liberal disdain inspires so much more anger than the very real disdain of conservatives who see the poverty of places like eastern Kentucky as a sign of the personal and moral inadequacy of their residents.

One thing is clear, however: Democrats have to figure out why the white working class just voted overwhelmingly against its own economic interests, not pretend that a bit more populism would solve the problem.