President Joe Biden’s policy agenda is hanging by a thread. And the reason can be summarized in two words: Joe Manchin. (Well, also Kyrsten Sinema, but does anyone know what’s going on with her?)

Manchin, the Democratic senator from West Virginia — whose vote is essential given scorched-earth Republican opposition to anything Biden might propose — is reportedly against the Clean Energy Payment Program, the core of Biden’s attempt to take action on climate change, and wants to impose work requirements on the child tax credit, a key element in plans to invest in the nation’s children.

You might be tempted to view this impasse as an indictment of the United States’ wildly unrepresentative political system, which effectively allows the interests of a small state — West Virginia has substantially fewer residents than the borough of Brooklyn — to dominate national concerns. But it’s actually worse than that: Manchin appears ready to veto policies that would be in the interests of his own constituents.

Let’s talk about what considerations should sway a politician serving the people of West Virginia.

West Virginia might seem less exposed than many other states to the effects of climate change. It’s landlocked, so rising sea levels aren’t a direct threat; it’s relatively rainy, so it’s not in immediate danger of sharing in the disastrous droughts afflicting the U.S. West.

But climate change is bringing more severe weather in general, including more heavy rain — and West Virginia turns out to be extremely vulnerable to flooding, in part because of the damage done by past coal mining.

Still, doesn’t West Virginia’s economy depend on continued use of coal, whatever the environmental effects? The answer is that coal is far less important to the state than it used to be, and its significance is doomed to dwindle no matter what we do about climate change.

What about other fossil fuels? Thanks to fracking, West Virginia has become a significant oil and gas producer. But this industry generates remarkably little income for West Virginia workers. In general, the returns to fracking in the Appalachian region seem to have gone overwhelmingly to outside investors.

In addition to blocking climate action, Manchin seems determined to cut back aid to children, in particular by imposing a work requirement for the child tax credit.

One way to think about that is it’s an attempt to force adults into work by holding their children hostage. Also, adding conditions to aid creates hassles and complexity — and the children who need this aid the most come from precisely the families least able to navigate this complexity.

What’s really striking, however, is to hear these demands coming from a senator who’s supposed to be representing West Virginia — a poor state with far more to gain from expanded aid to children.

Making child allowances contingent on parents finding work, while a bad idea in general, is especially bad for a state like West Virginia, where jobs are hard to find.

Adults in their prime working years are substantially less likely to be employed in West Virginia than in the nation as a whole. Economic change has stranded substantial parts of the U.S. heartland, leading to a loss of job opportunities.

Growing regional economic disparities are a serious problem, with no easy solutions. But it’s sheer cruelty to refuse to help children unless their parents take jobs that may not exist — and the cruelty is most intense in a troubled state like West Virginia.

So what is Manchin thinking? Some people say we should just follow the money — the large campaign contributions he gets from the fossil fuel industry, his personal financial stake in the coal industry.

But the most cynical takes on politicians’ behavior aren’t always right. I’d like to hope that Manchin is sincere — that he actually believes that he’s protecting his state’s interests.

The problem is that he seems to have a decades-out-of-date vision of what his state needs. And that distorted vision is now endangering America’s future.

Krugman is a columnist for The New York Times.