This is my experience arguing with my lib friend, like once a left position becomes mainstream (like Medicare-for-all) he will just pretend that's what he was fighting for the whole time without any acknowledgement of all the times he's argued against that very thing. However he will also not apply the leftist argument to another position which hasen't become mainstream like a housing garentee or free college.

if they just admit that they were wrong, or not even that, just give some weight to the opinions of the people who were right the whole time, it would all be fine. this will never happen.

yeah its why i don't bother trying to convert libs. they're a fucking lost cause, and they're going to get us all killed. if the fascists don't handle that first.