I have no idea what Joe Biden “really” believes about working with Republicans. But I will say this: he’s a politician. There’s zero reason to think he truly believes what he’s saying here. There’s also zero reason to think he doesn’t believe it. The fact that he said it is simply a null input.
At the same time, Biden isn’t an idiot. Of course he knows what the modern Republican Party is like. But like Obama before him, he also knows that lots of people really like to hear paeans to bipartisanship. We political junkies may hate it, but ordinary people who don’t inhale cable news are suckers for the idea that we can all get along if we just give it a try—and there are way more of them than there are of us. Biden knows this, so that’s what he tells people. Whether he really believes it or not matters not a whit.It is strange, when one thinks of it, that the possibility that Biden is simply mouthing a platitude that appeals to Joe Average Voter but which he knows full well is probably BS doesn't even occur to us. After all, I myself have talked a bit about the importance of being earnest -- of keeping a straight face and talking about bipartisanship and norms and neutral rules of procedure, even if one really is planning to string the opposition up by its entrails.
I'm not saying Biden is making this play. He's certainly the sort of beltway lifer that could be convinced that the modern GOP can be bargained with. But he also might be the sort of savvy inside player who understands that's now impossible. The whole problem is that either possibility should observationally yield Joe Biden singing the praises of bipartisanship.