We've seen Democrats successfully Do The Thing before but where they usually get hung up is feeling that The Thing is not working right away so they stop doing it when what you need to do is continue talking about until everyone is sick of hearing about it.
They usually stop when they are sick of talking about it, which is well, well short of "everyone is sick of hearing about it." Keep going. Don't shut up about it until people on the street are automatically filling in the next three words when you say "convicted..."
A way you'll be able to tell this is working by the way is that someone like Brett Stephens or Jon Chait will write a column like "I'm worried that Joe Biden doesn't seem to have a message beyond saying 'convicted felon Donald Trump' over and over." That means you're drawing blood. Keep going!
Stretching the truth slightly in order to compel the other side to defend themselves by repeating 90% of your attacks is a classic GOP tactic that Democrats need to try more often.
