Hillary Clinton won the popular vote by more than two million, and she would probably be president-elect if the director of the F.B.I. hadn’t laid such a heavy thumb on the scales, just days before the election. But it shouldn’t even have been close; what put Donald Trump in striking distance was overwhelming support from whites without college degrees. So what can Democrats do to win back at least some of those voters?

Recently Bernie Sanders offered an answer: Democrats should “go beyond identity politics.” What’s needed, he said, are candidates who understand that working-class incomes are down, who will “stand up to Wall Street, to the insurance companies, to the drug companies, to the fossil fuel industry.”

But is there any reason to believe that this would work? Let me offer some reasons for doubt.

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.

Beyond this, the fact is that Democrats have already been pursuing policies that are much better for the white working class than anything the other party has to offer. Yet this has brought no political reward.