This is fast becoming a Biden-Warren race (sorry Bernie), as more (now 4) Dems drop their bids, and others fade. Who do we see as potential running mates? Biden/Harris (patch the rift)? Biden/Beto (sub O'rourke for O'bama)? Biden/Klobuchar? Warren/Booker? Warren/Buttigieg (wonk power!)?
I know centrists and media like pushing that narrative. Much like Centrism and incrementalism, it's been shown to be hollow and lacking any meaningful evidence to back the claim.
other than, I suppose, facts and polling? What criteria do you propose, my friend? Wishful/magical thinking?