Trump's enemy is himself, best way to beat him is get him to take himself apart.
Only Biden and Warren seem to be able to pull this off better than Hillary for sure.
I don't see anyone else on the D side being able to figure out a way not to take damage and completely crumble against Trump's type of attacks. Pretty much anyone would get angry and/or flummoxed...they wouldn't even be able to wall that crap off and redirect the attacks back. Least Hillary did that.
Biden is definitively overrated. He's a more electable candidate nationwide than Ryan, to be sure, but he's still too gaffe-prone to be unbeatable.
Gaffe-prone is obviously the new rage [otherwise Trump wouldn't have ever had a chance]. And unlike Trump, Biden can take as much as what he dishes out.