Not saying you should vote for Biden, I think you should not (and instead vote for something cool like, idk, PSL or whatever the fuck you guys can vote for, just to give them enough votes for the uptick to be on the radar). But when you're talking to people who are going to vote for Biden, just don't dwell too much on the thing. It's not worth it, it is quite likely you will just piss them off, and chances are you won't convince them. If you want to talk about how both Trump and Biden suck, alright. It's just... I can see how this could push their buttons very easily. Just my opinion.
Don't shame people. Electorialism is a fuck, voting is sometimes good. Focus on the disappointment of Biden and is overseas policy issues, how you can't blame anarchists and revolutionaries for not voting for someone their own political theory fairly strictly tells them not to, and that the vote is basically a conscience vote.
This.