Rise and Fall of Stalin by Robert Payne.
Are the ones you mentioned more recent? The one I read was written in the 1980’s I believe.
I would say Biden is more like the Chernenko of our times, you may faintly remember the guy, he filled in between Andropov and Gorbachev around 1983-85 and was also senile.
The only thing that may require solving about Biden is whether he knows what is actually going on, or comes into work thinking he’s in charge (when clearly he is not).
I suspect he doesn’t know and is too stunned to get it, probably thinks he is the greatest president since FDR and will be on Mount Rushmore. Obama meanwhile knows he will be on Mount Rushmore II, the four great modern presidents, it’s only a matter of time until that gets suggested. And you can guess who the other three will be — JFK, Clinton and Eisenhower to give it a cover of credibility.
I once read that there are more books about Stalin than there are about anyone else except for Jesus Christ and Napoleon Bonaparte. However, most of these were probably published in the East Bloc.