This subject haunts him more and more. “If we’re trying to figure out how to advance the next generation’s future, we need to be spending more on the next generation, and we’re spending it on yesterday’s generation,” said Kerrey, 70. “I am not the future. My 12-year-old son is. But if you look at the spending, you’d think I’m the future.”

Kerrey is referring mostly to Social Security and Medicare, which, along with Medicaid, are the so-called entitlements that claim a larger and larger share of the federal budget.

He’s fixated on those sorts of numbers: According to the Congressional Budget Office, Social Security, Medicare and Medicaid totaled 6.7 percent of the country’s gross domestic product in 1990. By 2010, they were 10 percent. And by 2038, such spending may represent 14.3 percent. It’s hard to see how that leaves much money for discretionary spending on infrastructure, on education, on research, on a range of investments that safeguard or improve the America that today’s young people will inherit.

And there’s too little money for that even now. Talk to physicians and other scientists who have long depended on research grants from the National Institutes of Health to keep the United States at the forefront of invention and innovation and they’ll tell you how thoroughly that spigot has closed over the last 10 years. They’re defeated, despondent.

The Urban Institute released a report in 2012 that looked at figures from 2008 for the combined local, state and federal spending that directly benefited Americans 65 and older versus spending that went to Americans under 19; the per capita discrepancy was $26,355 versus $11,822. Julia Isaacs, a senior fellow at the institute, told me that while data for subsequent years hadn’t been analyzed yet, it wouldn’t show a significant change in that gap.

Isaacs also drew attention to a follow-up report released by the institute last year. It projected federal spending in 2023 and envisioned that entitlement payments to older Americans would rise to 46 percent of the budget from 40 percent now. Interest payments on the debt would be another 14 percent. That would leave well under 50 percent for everything else, including the military.

She noted that the population was aging. Meanwhile, there’s a resistance to tax increases. “That makes me very worried that children will be squeezed out,” Isaacs said.