A quarter-century ago, amid a political environment obsessed with the decline of “family values,” a book was published that methodically blew holes in the myth-making at the heart of this outlook.

The title summed it up: “The Way We Never Were: American Families and the Nostalgia Trap.” Stephanie Coontz’s 1992 book was a work of first-rate history, and it undermined a slew of common misperceptions of family life in America, but it was also a plea to take off the rose-colored glasses that cause us to get so many political issues wrong.

Fittingly, Coontz’s publisher, Basic Books, has released a revised edition just as the moralizing we’ve come to expect from presidential campaigns kicks into overdrive.

You’ll recognize the common conceits: that families must have two parents at all cost; that some people thrive while others fail based on their self-reliance; that private enterprise is the sole engine of economic growth.

Coontz, a professor at Evergreen State College in Washington, is research director at the Council on Contemporary Families, which highlights her work and that of similar scholars. It’s always enlightening.

Here’s the problem she consistently highlights, one that is endemic to politics: Twist the past and base current public policy on these misperceptions, and you will end up with a destructive effort that exacerbates the problems of inequality.

You can’t make America great “again,” a la Donald Trump, if you are clueless to what work life really looked like for most of the 20th century.

You can’t restore traditional family values, a la Ted Cruz, if you start with an interpretation of family that never existed in America.

And you certainly won’t resonate as a ceiling crasher for women, a la Hillary Clinton, if you continue to encourage policies and business structures that promote inequality between men and women and high- and low-wage workers.

Yet it is from this stewpot of historical illiteracy that many politicians ladle out their rhetoric, and voters gobble it up.

When the book was first published in the 1990s, experts of the day were wringing their hands over a range of issues: increasing rates of out-of-wedlock childbirth, numbers of single mothers, women in the workforce and welfare dependency. So many of the studies seemed to focus on women and the imagined threats from their changing roles in society — especially the threats they posed to children.

Yet what Coontz discovered back then would still be news to many: “I found that the male breadwinner family of the 1950s was a very recent, short-lived invention and that during its heyday, rates of poverty, child abuse, marital unhappiness and domestic violence were actually higher than in the more diverse 1990s.”

Here’s another tidbit: Almost a quarter of 1950s brides were pregnant on their wedding day. Keep that in mind the next time you hear a politician alluding mistily to the chaste and virtuous past.

So often we hear that unwed motherhood is a primary cause of poverty and economic insecurity. But Coontz cites current studies showing that income inequality is four times more important than family structure in explaining the growth in poverty.

Getting the story on poverty right is hugely important. It would force any honest politician to focus on things more likely to affect families: quality educational opportunities, access to childcare and family leave policies.

And those advantages are where America, in comparison to other industrialized countries, has really fallen down in recent decades.

Finally, there is what Coontz terms the myth of self-reliance. This one trips up Republicans and Democrats alike. It starts with a revisionist understanding of the role government has long played in aiding businesses, mortgage holders, farmers and college students, as well as the poor in various benefit and tax-credit programs.

Yet only some people are singled out as “takers”: minorities, single mothers and the like. The point is to make slashing their benefits seem like an act of fairness. After all, it is reasoned, it’s important to make people self-sufficient as well to balance state budgets.

“Legislators remain wedded to the historically disproven notion that subsidies to banks and corporations create jobs while subsidies to families create only laziness,” Coontz writes. The data say otherwise.

Remember that the next time a politician starts talking about his family’s humble beginnings and claims “we always stood on our own two feet.”

Media, it must be said, often echo these false narratives — perhaps because it’s so easy. What Coontz’s invaluable research shows us, though, is that to help families we must first understand them. Many of our politicians aren’t really trying.

Mary Sanchez is an opinion-page columnist for The Kansas City Star. Readers may write to her at: Kansas City Star, 1729 Grand Blvd., Kansas City, Mo. 64108-1413, or via e-mail at msanchez@kcstar.com.

(c) 2016, THE KANSAS CITY STAR. DISTRIBUTED BY TRIBUNE CONTENT AGENCY, LLC

Photo: U.S. Senator and former Republican presidential candidate Marco Rubio hugs his family after he announced that he is suspending his campaign at an event in Miami, Florida, March 15, 2016. REUTERS/Carlo Allegri