The answer, I’d suggest, goes beyond the fact that children can’t vote, while seniors can and do. There has also been a poisonous interaction between racial antagonism and bad social analysis.

These days, political support for programs that aid children is surely hurt by the fact that less than half the population under 15 is non-Hispanic white. But even before immigration transformed America’s ethnic landscape, there was a widespread perception that programs like Aid to Families With Dependent Children basically helped Those People — you know, the bums on welfare, the welfare queens driving Cadillacs.

This perception undermined support for spending on children. And it went along with a widespread belief that aid to poor families was creating a culture of dependency, which in turn was the culprit behind social collapse in America’s inner cities. Partly in response, aid to families, such as it was, increasingly came with work requirements, or took the form of things like the earned-income tax credit, which is linked to earnings.

The result was a decline in assistance for the poor children who needed it most.

At this point, however, we know that cultural explanations of social collapse were all wrong. The sociologist William Julius Wilson argued long ago that social dysfunction in big cities was caused, not by culture, but by the disappearance of good jobs. And he has been vindicated by what happened to much of the American heartland, which suffered a similar disappearance of good jobs and a similar surge in social dysfunction.

What this means is that we’ve established a basically vicious system under which children can’t get the help they need unless their parents find jobs that don’t exist. And a growing body of evidence says that this system is destructive as well as cruel.

Multiple studies have found that safety-net programs for children have big long-term consequences. Children who receive adequate nutrition and health care grow up to become healthier, more productive adults. And in addition to the humanitarian side of these benefits, there’s a monetary payoff: Healthier adults are less likely to need public aid and are likely to pay more in taxes.

It’s probably too much to claim that helping children pays for itself. But it surely comes a lot closer to doing so than tax cuts for the rich.