Biden would do less damage.
Harris is mentally smarter and lawyer smarter and would do the worst damage.
The Butt guy surely won't win and have his husband in the White House - Sodom, anyone?
Kinda agree with that.
Biden has the best chance of playing to the right of Tump, and therefore, probably the best chance.
He is also a palatable compromise to the two primary monied factions - Clintons and Obama - so more of a unity candidate.
Harris could be divisive, Clintons v. Obama, but is far more a 'true believer' and calculating. Far more dangerous... And probably viewed as more likely to survive Tump... While the opposite is true (Biden more likely to survive)... Still, because of their view, probably the pick in the end.