Journalistic power couple Nicholas D. Kristof and Sheryl WuDunn begin their latest book, “Tightrope: Americans Reaching for Hope,” with an epigraph from Dr. Seuss:

So be sure when you step,

Step with care and great tact

And remember that Life’s

a Great Balancing Act.

This bit of wisdom comes from “Oh, the Places You’ll Go,” and it seems a puzzling choice for a book that explores the “unraveling,” as the authors put it, of the white working class. Kristof and WuDunn’s book is about the death of the American Dream. In contrast, “Oh, the Places You’ll Go,” a perennially popular graduation gift, features a chipper, self-actualized little white fellow who is definitely on the path to greatness:

You have brains in your head.

You have feet in your shoes.

You can steer yourself

any direction you choose.

Perhaps, then, the Seussian epigraph is ironic: While the men and women whose stories are told by Kristof and WuDunn also start off with brains in their heads, they mostly find themselves, unlike Seuss’s unnamed hero, steering straight into brick walls and catastrophic collisions.

The book’s first chapter begins in a town with a fittingly Seussian name: Yamhill, Ore., Kristof’s childhood home. But there is nothing humorous about the opening vignette. It’s 1973, and Dee Knapp has to flee her own house when her abusive husband, Gary, points his rifle at her. It’s not a happy scene: Dee hides outside as Gary fires drunkenly into the night, and she prays he won’t take his rage out on any of their five young children.

And yet, Kristof and WuDunn note, in 1973, Dee Knapp still had reason to feel hopeful about her family’s future, despite the flying bullets. She and Gary had grown up poor, “without electricity or plumbing. . . . Gary had had virtually no education and could barely write his name.” But he found “a good union job . . . earning a solid income even if he spent much of it in the bars in Yamhill,” and Dee found steady work, too. The couple was able to buy their own home, and their five children all attended school. “For ten generations, [Dee’s] forebears had struggled to scratch from the earth enough to eat, and now finally in her generation there was dizzying progress.” Her children, she imagined, would inherit “a cornucopia. Electric lights. Tractors and cars. Education. Television. Medicare.”

But unlike “Oh, the Places You’ll Go,” whose plucky protagonist faces only the most temporary of setbacks, most of the characters introduced in “Tightrope” are careening toward tragedy. By 2019, all but one of Dee Knapp’s children would be dead: Farlan, “a talented wood-carver and furniture maker,” died of “liver failure from drink and drugs.” Zealan “burned to death in a house fire while passed out drunk. Rogena . . . died from hepatitis linked to her own drug use. Nathan burned to death when the meth he was making exploded.” Dee’s only surviving child, Keylan, was recognized by his grade school as a math prodigy, but he ended up spending 13 years in prison and emerged with HIV and hepatitis.

Why couldn’t the Knapp children climb the mountains so breezily summitted in “Oh, the Places You’ll Go” — or, for that matter, by Kristof himself, who catapulted from Yamhill to Harvard and thence to a prizewinning career at the New York Times? Or WuDunn, the daughter of poor Chinese immigrants who likewise soared to Harvard and the Times?

“Tightrope” seeks to answer these questions, interlacing the stories of ordinary Americans like the Knapps with the story of how America “went off track” around 1970, “beginning a nearly half-century drift in the wrong direction.” Readers meet more Yamhill residents, including Kevin Green, a high school friend of Kristof’s. At first, things look promising for the upbeat and generous Kevin, but a good job ends when the company he works for goes belly up. Kevin gets a worse job, and when that company also goes bust, so does Kevin. Unemployed, depressed and angry, he starts drinking. He develops diabetes and injures his back; he can’t pay child support, so he loses his driver’s license. He becomes obese. His organs fail, and he dies in 2014.

The problem, Kristof and WuDunn emphasize, is not that Kevin — or the Knapp children, or any of the others whose large and small tragedies are recounted in “Tightrope” — is abnormally weak-willed or irresponsible. The problem is that most ordinary Americans live their lives one small step away from catastrophe.

For the affluent, Kristof and WuDunn observe, “life’s journey . . . is like a stroll along a wide, smooth path, forgiving of missteps.” Lost jobs, breakups, medical bills, even brushes with addiction and crime aren’t necessarily catastrophic; money buys second (and third, fourth and fifth) chances.

“And will you succeed?” Seuss asks the protagonist in “Oh, the Places You’ll Go.” But for the well-heeled, it’s a largely rhetorical question:

“Yes! You will, indeed!

(98 and ¾ percent guaranteed).”

Nice odds, if you can get them, but the Kevins of the world generally can’t. “For those from lower on the socioeconomic spectrum,” write Kristof and WuDunn, “life resembles a tightrope walk. Some make it across, but for so many, one stumble and that’s it.” Poor and working-class Americans start out with countless disadvantages, and the social safety net that ought to help them recover from missteps has been systematically slashed by 50 years of mean-spirited social policy — even as corporations and the wealthy have enjoyed steadily growing government subsidies and a steadily more permissive regulatory environment.

The personal stories in “Tightrope” are, variously, wrenching and inspiring: From Yamhill to Baltimore, New York, Texas and Boston, Kristof and WuDunn offer narratives of those who have triumphed against the odds (children from stable, loving families that place a high value on education — like Kristof’s and WuDunn’s — are more likely to make it) as well as the painful stories of those who have been slowly ground down. But the litany of policy failures they describe will already be familiar to most readers: The war on drugs, over-criminalization, high health-care costs and inadequate schools are not breaking news, and too often, the powerful stories Kristof and WuDunn offer are buried in a blizzard of statistics and policy cliches. (“There are no magic wands.” “We as citizens must . . . hold all politicians’ feet to the fire.” We must “nurture understanding, empathy and a willingness to offer helping hands.”)

The intended audience for “Tightrope” isn’t clear. The authors inform us that their main goal is to “tell stories” rather than explore “policy alternatives,” because only storytelling is likely to convince conservatives that the woes of the working class can’t just be chalked up to personal irresponsibility. But Kristof and WuDunn feel they must cite an academic expert for this insight (“Harvard’s David Ellwood”), and by its final chapter, “Tightrope” turns into a laundry list of standard liberal policy recommendations. America, Kristof and WuDunn say, must take steps to ensure high-quality early-childhood programs, universal health-care coverage, higher minimum wages and stronger labor unions, for instance. On these points, conservatives are unlikely to be persuaded, and liberals are unlikely to require persuasion.

“Tightrope” also slides over some of the toughest issues it raises: Do the problems faced by the white working class and by working-class people of color have the same causes and solutions? Why do so many poor white Americans support President Trump, whose policies will probably leave them even worse off? And why do so many working-class Americans, both black and white, remain so ready to believe that their problems stem mainly from failures of personal responsibility?”

Undaunted by these unresolved questions, Kristof and WuDunn offer readers an upbeat appendix: “Ten Steps You Can Take in the Next Ten Minutes to Make a Difference.” (“Try supporting education for at-risk kids,” or “Consider volunteering at a homeless shelter.”) Readers are also urged to harness their book clubs to “tackle one issue,” because, Kristof and WuDunn note brightly, “it’s always more fun to tackle problems together.”

And so we come full circle. As that far more subversive Seussian figure, the Cat in the Hat, once famously observed, “It is fun to have fun, but you have to know how.” Kristof and WuDunn do not quite know how. “Tightrope” is earnest and oddly endearing, but often slightly muddled; the authors want to speak to conservatives as well as liberals, but they can’t quite pull off their own balancing act.

Perhaps this is because their opening epigraph from “Oh, the Places You’ll Go” is incomplete. Kristof and WuDunn neglected to include the final two lines of the passage they quote:

Just never forget to be dexterous and deft.

And never mix up your right foot with your left.

Tightrope

Americans Reaching for Hope

By Nicholas D. Kristof and Sheryl WuDunn

Knopf. 304 pp. $27.95