There was a fascinating moment in Paul Ryan’s press conference a few moments ago. It was quick and tucked into a conversation about “entitlement reform.” But it was bracingly specific. Ryan noted that to avoid steep cuts to programs like Social Security and Medicare, American women will need to start having more babies. Here’s the video.

Paul Ryan lays out new Soylent Green agenda. Says women need to have more babies if we want to avoid big Social Security and Medicare cuts. pic.twitter.com/LMdY2msAfN — Josh Marshall (@joshtpm) December 14, 2017

Here’s what is important to understand. As Americans live longer and have fewer children, the political economy has needed more young people than what economists call ‘natural increase’ can manage. That’s a key reason why relatively high rates of immigration has become so key to sustaining not just economic growth but the ability of working age payroll taxes to sustain these programs which mainly but not exclusively go to older people. There are other ways to help these programs: like ending the tax breaks that allow wealthy people to pay lower rates than working people.

But fundamentally, we do need more working age people. That’s where immigration has been so key. Ryan is being quite candid here. With the dramatic reductions the GOP wants in immigration as well as the tax cuts he’s pushing, he needs American women to start having a lot more babies. As he says he’s “done his part.” Ryan and his wife Janna have three children.