Same as the idea that people get more conservative as they get older, which of course implies that if you’re left wing you are in fact simply immature

Uh, I'd read older meaning cognitive decline: as one gets more senescent one gets more conservative. Did people read this as getting wiser with age?

I can’t believe that narrative has survived the era of Trump

Getting older. Positively middle aged for a few years now. Got more left wing. And not in a “can’t afford a house so I’m not turning conservative/taxes” version. Neither of my parents got more conservative either, so I think it runs in the family.