[defen]

There's a bit of the tragedy of the commons at work here. Raising kids is expensive, difficult, often thankless work. And yet if no one did it, you wouldn't have any of the nice things that are more-available to people who don't have kids. Furthermore, given that political attitudes appear to be strongly heritable, it seems like the political attitudes that correlate with the class of people who deliberately don't have kids will also wane.