I have mixed feelings about George W. Bush and his refusal to get involved in this.
Up until Trump came along, he was arguably the least popular President in modern history ('arguably' only because Nixon, if he still counts as 'modern.') Liberals hated him with a passion and many still do, and nowadays he's what MAGAs would call a RINO.
Would his endorsement help Kamala's chances or hurt them? I could make a case either way, but honestly, I don't know. Maybe he doesn't either.
Not giving him any marks for courage, but it's possible his staying out of it might be for the best.