At least in the US, fertility rates are much lower on the left.

This piece is a few years old, but I've seen updated surveys that indicate the trend has continued: https://www.aei.org/articles/the-conservative-fertility-advantage/

> the collapse of fertility on the political left

Not sure I understand. I guess, you have seen some data? Anyway, Caplan makes some interesting points.

oliverweiss

econ

Bryan Caplan on What Natalists Should Learn from LGBT

I hadn't thought about that before, wrt LGBT. In general, the collapse of fertility on the political left is going to make future generations very different from ours.