No one will care about that because he’ll end the rancor between Hillary and Bernie. All of that will be barely spoken about, if mentioned at all. He will be portrayed as the white knight unifying the fractured Democrat party.
Trump will go after him, the way he’s gone after everyone else. “Clueless Joe” or some sort. Maybe that sticks, maybe it doesn’t. No matter what, once Biden chooses Warren as his running mate, he will have the a united Democrat party at his back. That’s a serious problem, regardless of how much an idiot he is.
My friend, you're grossly underestimating the "rancor" and animus between Hillary and Bernie's supporters. These people plat dirty and hold grudges that make the #NeverTrump people beef look like playful spat.
The DNC has an irreparable problem on their hands. If they insert Biden and Warren, THEY will be resented as having hijacked the nom from both The Hag and The Bern.