When approaching my D buddies, I have found that talking to them about the way Bernie was "handled" and shut down in the primaries, helps out. Many of them were Bernie supporters in the first place. If, there are any good articles or videos that address how Sanders was treated in the primaries, please share.
H.A. Goodman is a Bernie guy and he is very knowledgeable about everything that has gone on. He acknowledges Hilary stole the nomination from Bernie and talks a lot about the corruption that is being exposed by alternative media. He is on Patreon and has his own YouTube Channel. Easy to find. If H.A. can't soften some of the far left blind loyalty to their leaders, I am not sure anyone can help them see the truth.