In 2016, sure. But Trump will have muddled through 3+ years of Oval office buffoonery by 2020. His populist message will not be what it once was.
LOL, Jesus, no.
Liz Warren fires up the base. Her base is Bernie's base PLUS a fair portion of the center-left. Among the two, only one openly calls himself a democratic socialist, and that ain't Warren.
She would pull more support from rank-and-file Dems in a general election against Trump than Bernie would. Nobody would sit that one out. The only question mark would be the D to R crossovers, but that would apply with any Dem candidate.
This right here. A centrist would make a great VP candidate, but they aren't likely to win the nomination. Instead, aside from Biden, who can run on name recognition, the 2020 Dem nominee will meet one of two criteria:
1) Be a political shape-shifter, someone who is less tied to policy positions and able to change them as need be, ala Kirsten Gilibrand.
2) Be a bona-fide lefty with some crossover appeal. Warren and Sanders both fit this.