At the national conference of the American Academy of Pediatrics (AAP), I got to hear Hillary Clinton talk about the AAP’s partnership with her Too Small to Fail campaign. It made me happy — and sad.

The partnership is a great idea. It’s all about improving early childhood literacy, which is way more crucial than most people realize. It’s not just about an income gap when we talk about the fact that 1 in 5 U.S. children live in poverty. It’s also about the word gap.

Kids who grow up in low-income households hear fewer words than kids who grow up in more affluent ones. Millions fewer, actually (30 million by kindergarten). This makes a difference, because kids who hear more words have bigger vocabularies at age 3 — and not just do better in school, but have higher IQs. The word gap turns into an achievement gap which leads to an income gap which leads to a word gap … you can see where this is going: The divide between rich and poor gets bigger and bigger.

When they’ve looked closely at this word gap thing, it turns out that all families have roughly the same amount of “business talk”: Come here, don’t hit your brother, eat your vegetables, do your homework, and other such communication. Where the word gap lies is in the “non-business” talk: the chatting, the encouragement, the singing — and the reading.

Did you know (Clinton told us this) that in middle income neighborhoods, there are an average of 13 books for every child — while in low-income neighborhoods, there are 300 children for every one book?

While the amount of time spent meeting the physical needs of children (like changing their diapers or feeding them) has remained the same over the years, the amount of Goodnight Moon time has dropped — especially among low-income children. That’s where this campaign and partnership comes in, by helping pediatricians encourage parents to read and interact with their kids (and helped by a big book donation from Scholastic Books).

It’s wonderful. But as I sat there listening, I felt a bit sad.

I’ve been a pediatrician for 23 years, working with many low-income families. I’ve been lucky that our hospital is part of the Reach Out and Read program, meaning that I’ve been able to give books to families when they come for well-child visits, and talk with parents about the importance of reading and talking to children. I’ve been doing this for years.

I’m sure I’ve helped. But the lives of my patients haven’t gotten appreciably better. As Clinton herself pointed out, the number of children living in poverty is higher now than it was in 2000.

The thing is, there’s so much a book and a pep talk from me can’t do. They can’t teach a parent to read. They can’t make it so that a parent is home at bedtime, instead of working the evening cleaning shift while an older sibling or neighbor watches the child. They can’t get rid of the toxic stress that pervades every family interaction.

This is a lovely campaign. I’m happy it exists and I wish it all the best. But kids don’t vote, the parents of poor kids don’t contribute to campaigns (and many of them don’t vote), and the fruits of “Too Small to Fail,” if any, won’t be seen until long after the next election cycle or tenure of any current captain of industry. We are a society that is all about its wallets — and its politics.

Jim Steyer, the founder and CEO of Common Sense Media and Clinton’s partner in Too Small to Fail spoke at the AAP earlier the same day as Clinton. He pointed out that we are investing trillions in Iraq and Afghanistan, but not in our children.

“The underinvestment in young people in this country is morally wrong and economically stupid,” he said. I couldn’t agree more.

But when it comes to those who are too small to fail, are we perhaps too big to care?

Claire McCarthy is a pediatrician at Boston Children’s Hospital. She blogs at the Huffington Post, where this article originally appeared, and at Boston.com as MD Mama.