Do you find that liberals sometimes or even often forget or suppress all memory of discussing politics with you?

This would happen with my dad, years ago. We would spend hours talking about politics. I would convince him that we basically live in the Confederacy, that the Confederacy lost the battle but won the war (since slavery is still an important part of the American economy), and he would agree, and then the next time we spoke, within a few days, it would be as though our lengthy conversation had never taken place. He was back to "everything will be fine if we just get rid of Trump" mode.

These days I'm stuck for lengthy periods of time in the company of another lib. This one is younger and much more aggressive, but as usual liberalism just isn't up for a fair debate with Marxism. I talked about slavery in the USA with this guy recently, and he told me that it's not a big deal because the USA isn't "explicitly" about slavery (???). After we had finished talking, I checked to make sure of something I suspected: the OG US constitution never mentions slaves. Even the 3/5 compromise only mentions "other persons" lol. It isn't mentioned until the passage of the thirteenth amendment—when it creates, in a stroke, jim crow and the prison industrial complex. So actually, before the civil war, slavery was "implicit," and after the civil war, it became "explicit"! I still managed to hit him with a "the purpose of a thing is what it does" and "we live in a genocidal slave empire" before we finished talking. And he just laughed. He has called my diatribes nihilistic and pessimistic. And I'm like...bro, I'm pessimistic about amerikkka, but optimistic about the world.

Interestingly enough, the Confederate constitution is word-for-word the same as the US constitution, except they threw in a few clauses about how slavery rules and no one should fuck with it. I haven't broached the topic of politics with this lib since then because I'm worried that it's going to cost me my job, but I just have the feeling that nearly everything I say to him doesn't matter anyway, that he forgets every word within minutes of separating from me, and just goes back to thinking about white people music (the only kind he listens to) and how we need to get the orange orangutan out of the damn white house. He got pretty angry when he was talking about how goofy republicans are for voting for politicians who screw them...and I was like, dude, how are democrats any different?

Anyone else have this experience or know what I'm talking about? If liberals had any kind of self-introspection, they wouldn't be liberals. The thing is, I can remember, when I was a liberal, being embarrassed on multiple occasions by people whose politics were further to the left than mine. Maybe I suppressed some of those memories, but a bunch of them still stuck in my conscious mind. Do they stick with liberals and do they just not talk about it, or was I just a confused Marxist all along?