Among postmortems of what happened to national Democrats on Nov. 5, the theme of working class, or blue collar voters breaking for Donald Trump comes up again and again.

It’s presented as if it were something new, but it’s not. In fact, we can precisely date the moment disaffection of working people for Democratic candidates reached critical mass.

It was the landslide election of Ronald Reagan in 1980, with its massive swing in favor of a candidate who promised to break unions, lower taxes for the rich and cut the domestic programs that offered a path to the middle class through housing, low-cost college and good public schools.

Thus were created the Reagan Democrats, and they have never gone away — nor does the Democratic Party seem to understand what it will take to get them back.

It may be simpler than we realize, though that doesn’t mean it will be easy to do.

For the Democratic Party has become unmoored from the ordinary people who supported them faithfully through the first two centuries of the Republic.

Republicans, and before them the Whigs, have always been the party of business — representing capital, corporations, billionaires, take whatever example you want.

But if Republicans can rightly be deemed the party of the 1%, then Democrats are at most the party of the upper 10%.

Joe Biden was the first avowedly pro-labor president since Harry Truman, and even Biden couldn’t do much for wage-earners because his party still can’t unite behind unions.

The necessity of doing so has been postponed through 11 presidential election cycles because Democrats sometimes win — barely. Reagan’s victory over Walter Mondale was the last truly decisive result, though George H.W. Bush enjoyed a healthy margin in 1988 — the nadir of Democratic fortunes.

Since then we’ve had mostly nail-biters. As for Trump’s recent triumph and Electoral College win, it doesn’t look convincing.

As western state vote-by-mail results trickle in, he’s fallen below 50% of the popular vote, with the result the fifth least decisive among 59 presidential elections.

Still, the reckoning can no longer be postponed. Democrats, having lost, must change.

The most important change is one of attitude. The much remarked division — college-educated voters favoring Democrats, while high-school graduates vote Republican — is completely artificial.

The real division, as it always has been, is between employees and owners, labor and capital, Main Street and Wall Street. Unless Democrats stand foursquare behind workers, they’ll never govern again with a solid majority.

Consider: During the pandemic many were appalled by what “essential workers” had to go through — face a life-threatening virus every day or lose their jobs, even while their children couldn’t attend school and their lives were in turmoil.

Since the coronavirus waned, we’ve forgotten about them.

What would have helped these essential, mostly low-wage workers more than anything else? Clearly, a union — the traditional ticket away from sweatshops, life-threatening safety hazards and impossible schedules.

Yet it’s more difficult than ever to form a new national union, and none have been. The Amazon and Starbucks workers who voted to unionize don’t have contracts, and with Trump’s return will never get them.

The giant industrial concerns employing millions of Americans are long gone, but the jobs where unions should be essential — hotels, restaurants, service workers of all kind — have no representation.

All the advantages accrue to corporations (including nonprofits) who have unlimited opportunity in most states to dramatize the terrible things that will happen if a union is formed, while organizers, if they can reach workers at all, must do so away from the workplace among those whose leisure time is scarce.

The first priority for Democrats should be rolling back decades of Republican efforts to disempower unions, making organizing campaigns fair and democratic.

Finally, there’s the problem of condescension, the college-educated looking down on those who work with their hands rather than their heads. It’s real, and apparently deep-seated.

Ultimately, all work is valuable, equally worthy of respect. Most Americans, even those well off, need a plumber more than a financial planner.

Protecting the vulnerable is a vital function of government, and still a bipartisan cause. But Democrats won’t succeed until they realize, as Gov. Joe Brennan often said, that the best form of welfare is a good job.

Once that’s established, essential programs for housing, alternative transportation, good public schools and free community college can stand as vital supports, not the sole focus of Democratic platforms.

Celebrating work is a patriotic cause, and if it involves a little capitalism-bashing, so be it. If that cause again becomes central to Democratic campaigns, they will succeed.

In the meantime, we can adapt a great slogan: “Workers of America, unite!”

Douglas Rooks has been a Maine editor, columnist and reporter for 40 years. He is the author of four books, most recently a biography of U.S. Chief Justice Melville Fuller, and welcomes comment at drooks@tds.net