another underrated aspect of the primary campaign was biden's perceived control of "the center." a lot of candidates who could have been really good centrist candidates (imo) like harris and sort of buttigieg (who tried a little harder to straddle the line) instead chose to tack to the left and go for those votes instead (especially harris). the road was open for harris to be "obama like" and be a centrist, prosecutor technocrat and she chose to triple down on being the twitter candidate. i mean, when asked about medicare for all they all raised their hands except kloubachar, i think.
in fairness to them, the candidates who tried to remain in the center (kloubachar and sort of buttigieg) never got any traction.
the dems nominating warren would be a gift to the gop. an old white woman liberal from TAXachusetts? that's the perfect liberal to run against. add in the native american stuff that they will continually bring up and she'd get slaughtered.