@blatham,
If somebody repeats a Sanders line as propaganda, it would have to be true, nonetheless. How could it falsely influence someone? Or if a propaganda piece points out the Democratic Party cheating against Sanders, we all know it happened, so how would we be influenced to change our course of action. I personally didn't see Russian propaganda pieces unless they were factual enough to fool me. But they did not influence me one way or the other, since I made up my mind before the primaries were close, just like this year.
As for Biden, I think people who seriously support him are influenced by propaganda, not Russian, but American media. They see an image of stability and must not be looking beyond a myth built around him. He has always been a right-wing character and he will squash any progressive initiatives. I consider him mostly braindead. If you want any increments you will avoid this guy.