Paige Black is a 24-year-old from northeast Philadelphia with a college degree in biochemistry and exactly the job she was aiming for, as a hospital lab technician. But she's also forced to live at home with her parents, middle-class retirees, and has no idea when she'll ever get a place of her own — all because of one thing she failed to calculate.

That is, calculate in the most literal sense of the word.

Her student debt. A whopping $130,000 worth. Black told me in a Twitter interview that it wasn't until she graduated from Chestnut Hill College that she realized the full impact of the 12% interest on the Sallie Mae student loan that financed her tuition. "It's impossible for me to move out," she said, even after renegotiating the monthly payments down to $600 a month, which essentially just covers the interest. "I have a car payment, car insurance, health insurance, bills, etc., so it's just ridiculous!"

Ridiculous, yet Black's plight is shared — albeit maybe not to that extreme degree — by millions of American voters. Many, though not all, are in their 20s or 30s, and many are found in the expensive-to-live urban areas where desirable jobs are increasingly clustered. They work, but struggle to find an affordable apartment or child care, or to pay off staggering student loans. They're often one medical emergency away from wiping out any minimal savings.

The existence of these voters helps to explain one of the greatest riddles of the 2020 presidential campaign: Why is there so much anxiety around pocketbook issues, when the Dow recently has touched a once-unthinkable record high and the jobless rate sits at a once-unthinkable record low?

In 1992, when a seemingly popular president in George H.W. Bush was felled by a recession, the victor Bill Clinton's chief strategist had a famous sign in his office: (It's) "the economy, stupid." Now 28 years later, can the Democrats take back the White House again with a slogan that amounts to "It's the affordability, stupid"?

For a number of years, America's growing yet hidden affordability crisis has been a little like the feminist Betty Friedan's famous 1960s description of the patriarchy as "the problem that has no name." This despite the fact that concern over America's $1.4 trillion-and-growing student debt, housing prices, and out-of-pocket medical expenses had fueled the rise of 2016 candidate Bernie Sanders and sparked increased interest in socialism from young voters.

In 2020, though, the problem is too big to ignore. In a recent article for the Atlantic titled "The Great Affordability Crisis Breaking America," writer Annie Lowrey tied the threads together with some mind-blowing stats on the extent of the problem. From her piece:

• Home prices have been rising faster than wages in 80% of the nation's metro areas, which has resulted in a lower home-ownership rate for millennials (the generation generally defined as people now in their 20s and 30s) than their baby boomer predecessors, even though rent has also been rising faster than income for two decades.

• More than 50 million Americans, including one of three people in their 20s, are seeing their earnings eroded by their college loan debts, which increased by an astronomical 116%, as tuition soared and young people embraced the idea that they would be unemployable in today's economy without a diploma.

• Lowrey's piece also calls attention to the less noticed affordability crises in child care costs — up 2,000% (that's not a typo) over four decades, and preventing many low-income women from working — and out-of-pocket medical expenses, the result of skyrocketing deductibles that means even those covered by Medicare or Medicaid may pay thousands of dollars in a typical year.

How is this not a national emergency? Part of the problem may be, to employ an overused 21st-century buzzword: branding. Lowrey's Atlantic piece was groundbreaking in seeing college debt, rents and other expenses as one common crisis, when they are typically discussed in their separate silos. And most financial and political journalists and analysts have grown up with a different, 20th-century worldview of what makes a great economy.

But the rising stock market is to some degree a barometer of how well corporations have steered growth toward shareholders at the expense of everyday workers. And the low unemployment rate has been pushed downward by jobs in "the gig economy," like Uber drivers, that typically aren't paying a living wage (let alone benefits) in the cities where these gigs are concentrated.

Last week, I posted on Twitter looking for young adults in the Philadelphia region who struggle with rent, college debt and other costs of trying to survive in a large metro area. I was surprised by the number of people who wanted to share their stories. I heard from the 33-year-old in South Kensington whose student loan repayments were equal to her mortgage payments, the 32-year-old who still needs two roommates in order to live in the city and the cyclist with the broken wrist who was bruised again, months later, by a surprise $800 out-of-network charge.

"The idea of putting a down payment on a house seems much more intimidating for people my age," Barry Tomasetti, a 26-year-old engineer working at the Philadelphia Navy Yard, told me. He and his fiancée will be sharing the $1,600-a-month cost of renting in Northern Liberties, but the American dream of homeownership remains exactly that: a dream.

The affordability crisis could be the secret sauce in the presidential race. Sanders' laserlike focus on making both health care and higher education universal (and free in many cases) and on increasing middle-class wages has been echoed in the 2020 race by Sen. Elizabeth Warren, who also wants to wipe away all existing college debt and to make child care more widely available through a wealth tax on millionaires and billionaires.

Young voters have taken notice. In the Democratic primaries so far, Sanders has a huge lead with under-35 voters while Warren has been placing second. Northeast Philadelphia's Black, with her $130,00 student debt, told me she's followed both campaigns. She applauded Sanders for protesting the closure of Hahnemann University Hospital, where she worked and was laid off before her current job, but also said that Warren "is a lot more smarter and can get [stuff] done." She added: "I've radically accepted that I'm going to die with my loans, so in a perfect world there would be no student loan debt."

Talk for just a few minutes to these young voters and you start to understand the disconnect between America's young adults and the mostly older pundit-and-politico class, which struggles to understand why Sanders is now the solid Democratic front-runner, and also wonders how Trump — despite his impeachment, his corruption and myriad abuses of power — can be beaten with "the economy" doing so incredibly well.

But the Democratic nominee in November — even if it's not Sanders or Warren — can take back the economic conversation if she or he can successfully rebrand what's happening to the average American household with that one word: affordability.

Because what good is the Dow at 30,000 or the slow and steady rise of the gross domestic product when those dollars are hoarded by large corporations, their shareholders and their CEOs, while their average employee lives in the cramped equivalent of a college dorm room, one bike crash away from insolvency?

What's more, the young and urban voters who suffer the most from the affordability crunch are the ones who, historically, vote in lower numbers; a surge in under-35 voter turnout would guarantee the election of a Democratic president, no matter how many Russian bots are posting pro-Trump memes on your great-aunt's Facebook page. If the opposition party is truly serious about making Trump a one-term president, it should embrace the 2020 equivalent of "It's the economy, stupid," which would be a blue hat reading, "Make America Affordable Again."

Will Bunch is the national opinion columnist for the Philadelphia Inquirer.