Obama could have picked anyone to be his vp, Biden was not a factor in that election, people voted for the black guy because of his skin color. Biden is not going to win this election, but his vp pick might help his chances, so what does he do? He picks a black person to once again ride into the Whitehouse, because people will blindly vote for the black person.
If someone of color or gender gets elected based on their OWN color or gender then all power to them. But biden is a WHITE MALE, so he's using people to gain political power.