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?
Because something that gets lost in the two party system is that, at its core, there’s the conservative side trying to make things best for their majority group and then there’s a dozen different types of liberals trying to make the world better in their direction. One side wants to revert back, one “side” is pulling in a hundred different directions. Should we tackle education first? Financial responsibility? Human rights? Social safety nets? Pollution? Climate change? National interest? Global interest? There’s so many different topics that liberals want to progress forward in an order each individual determines. It’s not a single liberal force, it’s a hundred forces in a trench coat. Conservatives (of any country or topic) are some kind of incumbent majority/dominating demographic while the alternatives all fall under “liberal”. So the only thing that consistently unifies the democrats is what they don’t like
Opposition to Trump is currently the strongest force uniting the Democrats, but I think there’s more dividing the Democrats than just a disagreement about which issues to prioritize.
For example, someone who prioritizes abortion rights usually also supports protecting the environment and vice versa. Most abortion-rights people and environmentalists agree about what the ideal end state is (both goals accomplished). However, someone who supports affirmative action and someone who opposes affirmative action may currently vote for the same candidate but they’re clearly opposed to each other in a way that the abortion-rights person and the environmentalists aren’t. The distinction between liberals and leftists is useful for describing many disagreements of the second sort, and it’s an important distinction because the dividing line between Democrats and Republicans won’t always cut across the same issues it does now.