I don't think Biden is quite the cold, calculating leftist Obama was.
Biden is more accurately described as being an opportunist who is looking for his main chance. The trend now in the Dem Party is extreme leftism, so that is now what Biden mutters when he says anything in public. If he can get the words out without being distracted by a shiny object or something else.
Like most pols he has an inflated ego as to how smart he thinks he is.
His problem is that maybe twenty years ago his mental faculties were still functioning at a normal, dishonest pol level.
But now it's obvious that whatever cunning he might have had years ago has now left him.
Doddering, old fool who will do or say whatever he's told more fits the description of modern day Joe Biden.