We just had an election here in the US, and if you look out across social media you'll see a lot of posts talking about how people are "voting against their interest."
This is a claim that comes exclusively from liberal democrats. For reference, "liberal" in the modern American context is not related to "liberal" in other countries. It's a fun history about how that happened with Roosevelt, but for a different post someday.
Here's why it's a dumb claim: it makes greed the only motivator to place a vote. The subtext here is that there are no principles to live your life by. Just go out and get yours regardless of the cost to others. The greed might be monetary or social in form.
This is the same group that says tax the rich out of existence, although "rich" is always that other guy instead of me.
They also say those rich people got that way by exploiting others out of greed.
So they are simultaneously claiming that you should act out of greed, but those who have acted out of greed and been successful should be punished.
It's literally nonsense.
On top of that, when they talk about women voting against their interest they mean access to abortions. On its own terms, it's not at all clear that women en masse would have their interests served by unrestricted abortions in the sexual marketplace. After all, women are in competition with each other for mates. Knocking out your competition by saddling them with children to take care of would raise your relative standing.
And finally, we have the fact that all value is subjective. Literally no one else can tell you what your interests are. The claim is both irrationally arrogant and stupid.