Exactly. But, most of my Progressive friends aren't even that sophisticated in their thinking. They are far too gone down the road of needing to control outcomes because of their personal fear of things not working they way they think in fair.
They simply cannot face the idea that what they want isn't what everyone else wants, or worse, should want.
I've noticed something. You are rarely going to witness someone change their mind WHILE you are having the discussion. That is very rare. However, you are planting seeds that they can think about over time. They are doing the same in you. It is very possible you DID convince them. It just takes time for that seed to sprout and grow.
So that is how I look at it. That makes me think it is worth the effort even if I don't see an immediate reaction.
I've seen someone who disagreed with me like you described that I debated with and nothing seemed to come of it. A year later I see him debating with some other people and he is where I was with him. So I did influence him, even though I didn't witness the transformation, I simply saw it later.
I can tell you that I've had that happen on dozens of occasions. Moreover, those watching the debate are usually swayed on the matter at hand more than the person you are arguing with.
And I never bring it up or say, "I told you so." I just note it, incorporate their new position with glee and move on.
The people I was referring to in my last comment I've been arguing these ideas for nearly two decades now and all that happens is either a 'I don't want to talk about this stuff' after they say stupid shit in my home or wait to pick the fight later with a new, more refined version of the old argument, which I skewer just as easily as before.
We're talking committed, Derrida/Foucault reading dyed-in-the-wool marxists here. They're not coming round until after the system crashes, if ever.
Yeah some people are intractable. They are locked into their paradigm and the only thing that causes a paradigm shift when someone is that LOCKED into how right they are is typically trauma, or some other shocking situation.