i made a gentle attempt at initial contact with the new person, and will start bombarding her with calls at 15:00. i need a straight answer by the end of the day.

you can try to explain this away however you want, but it's the fundamental point:

Sanders does better with those registered with no party (22%) than those registered as a Democrat (15%). (Biden shows a similar gap.) 

Warren, on the other hand, does better among Democrats (25%) than unaffiliated voters (12%).

This matches up with national polling that suggests Sanders voters are not anywhere near as pleased with the Democratic Party as Warren voters are. 

this was the same basic difference you saw in 2016, too: present warren supporters seem to be old clinton supporters rather than old sanders supporters, and that makes a lot of sense when you look at their actual policies. or you can be gender-reductionist. whatever.

i will continue to argue that sanders is in his own lane, the tricky part is trying to figure out what the other lanes are, even if they all merge in the end. i'm not sure we have enough of an understanding of things, yet.

for example, you could argue that harris is in competition with biden for the black vote and the big money donors. or, you could argue that biden is in competition with bootigieg for center-right voters, or that bootigieg is in competition with warren for the "progressive" vote. these things aren't clear yet, and i think it's partly why the numbers are all over the place - nobody's really sure how to model the data, yet. what that means is that these polls are essentially worthless.

but, if sanders thinks he's going to win this by swinging registered democrats, he's wrong. he's not being embraced by the party, and he's still going to have to overpower registered voters with independents and new voters.

he shouldn't be thinking he can pivot to front-runner; he needs to do exactly what he did last time, and he needs to do it better than he did it last time.

....because he's not a democrat, and democrats know it.