I will say that even less than a year ago I oscillated from Sanders to Warren, and that my vote would simply go for whoever was leading the other prior to the NY primary (April 28th). However, the last few months have made me increasingly weary or at least less enthusiastic of Warren, and while I unequivocally prefer her to the other candidates, my own political ideology, understanding of historical change and dialectics, and, frankly, the recent blunders made by Warren and her campaign, have convinced me to lend my full support for Bernie.
Warren and her campaign team have made a notable series of blunders that, to my mind, demonstrates poor political acumen. The Native American DNA fiasco demonstrated shoddy political judgement, particularly vis-à-vis prodding by Donald Trump. Had she made this decision now, any momentum her campaign currently has would likely screech to a halt. And while the Native American stuff hasn't and won't come up in the primary, you better bet that Trump will lean into it hard in the general. Additionally, her decision to first pursue a private-public healthcare option, only to then formulate a comprehensive Medicare-For-All legislation sans private insurance as late as her third year in office would effectively stifle the momentum that
bona fide Medicare-For-All would have and make it harder to pursue. Healthcare is consistently ranked one of the most important policy issues, particularly among Democrats, and Warren's waffling on the subject is
correlated with her atrophying support as she moved from the second place position, to third behind Sanders. She also mishandled the recent controversy with Bernie Sanders and potentially widened the animosity between the two camps which
could have repercussions in the primary and broader repercussions for a progressive/socialist alliance. There are an array other concerns (e.g. endorsing Clinton over Sanders in 2016, despite the latter encouraging her to run against Clinton...
and she probably would have won!) from policy to campaign judgement, but it's not my goal to be comprehensive here, just to outline a broad overview of objections.
And as cathartic as it may be to see Trump lose to a women in 2020, politics isn't aesthetics (liberals and conservatives often confuse it for one).
But my original reasoning for supporting Sanders over Warren is in their distinct theories of how social and political change occur. In true Democratic Socialism fashion, Bernie is (and has been since 2016) clearly focused on building and energizing a wider social movement so that even if he doesn't win the presidency, or after his political career is over, there is still a strong grassroots momentum to demand political change, which, beyond Sander's own message, is further substantiated by over 5M individual donors and donation numbers, rally turnout, and loyal following. Warren, while also having a solid donor and supporter base, nevertheless leans into a more technocratic approach, which locates social/economic/political changes not with a broader worker class-focused movement but with elite-decision makers (e.g. "Warren Has A Plan For That").
Meaningless. Each poll is only a single data-point ("snapshot"); it takes a series of polls to exhibit a trend (curve) of data-points from which a prediction can be inferred. — 180 Proof
The tense isn't exactly relevant, my point is that it's mistaken to claim there is a substantive overlap between Sanders and Trump supporters.