For the longest time, “liberal” seemed like it basically just meant “Democrat” the same way “conservative” has/had been used to mean “Republican.” Now, it seems like it means “bad Democrat” and is even worse than being MAGA the way many seem to use it. Where did its use as an insult within the [relative] political left come from, and what does it specifically accuse/identify someone of/as?
You might look up the term “neoliberalism” as I think there is a lot of overlap with the information you’re seeking and those who would be called liberal perjoratively.
Or “tankie”
Nah tankies are just people who push pro-China and pro-Russia propaganda. I haven’t even ever seen one of them actually talk about communism.
Neoliberalism is itself a postliberal framework that rejects many central tenets of classical liberalism.