but I'm not sure I'd waste much breath getting all his supporters to understand
No time required for Biden supporters. He get it. Supporters gets him.
If Biden was running against someone rational like Romney, then every time made a gaffe (and he will) it would be huge almost show stopping headlines. But in the Trumpy era where every time Trumpy opens his mouth, he spews out lies, what'a a few gaffes?
In 2016 Hillary tried to be prim and proper. While Trumpy threw shit her way. I did wonder if Biden would also be passive. But it may not matter with the Lincoln Project around. LOL