Every so often, you can see a take emerge in the takesphere that is so striking — so penetrating in its insight, so damning in its criticism — that it doesn’t really matter if it is actually true. And as far back as 2016, you could see this happening amid the “Bernie bro” complaints. In the early months of that year, Sanders supporters were parrying allegations of sexism by naming women who they preferred to Clinton — among them, Massachusetts senator Elizabeth Warren.
At first, the response to this was to suggest that Sanders supporters were simply being opportunistic: they’re only saying nice things about Warren, we were told, because she isn’t running for president. But by the end of the year, that line had evolved into a hypothetical: what if Warren did run for president, and all of the Bernie bros who are saying nice things about her now refused to support her?
The irony was too good to not be true. And so, in the years since, a new kind of Bernie bro was born: the Sexist Warren Defector.
Among Clinton dead-enders and Sanders concern-trolls, it’s just a point of conventional wisdom that the Sexist Warren Defector is a real historical figure.  This despite the fact that no one has ever actually demonstrated that these people exist. Just to be clear, here is what you would actually have to show:
1. People saying “I would vote for Elizabeth Warren over Bernie Sanders.” It is not enough to find people saying “I like Warren” or “I prefer Warren to Clinton,” because obviously you can say both things and still, with absolute consistency, think that Bernie Sanders is an infinitely better candidate.
2. That these same people who said they would back Warren over Sanders have now reversed their position and decided to support Sanders over Warren.
3. That there is a significant trend of Sanders supporters doing this. In a voting age population of over 200 million people, you can always find just about any kind of voter you can dream up, just as a matter of simple statistical inevitability; but what does this prove about anything? The Sexist Warren Defector is supposed to be proof of a significant bias that Warren faces among Sanders supporters; if this is true, it should be trivially easy to find thousands of instances of this on Twitter alone, where we have a massive archive of statements on the topic that people have been making for several years.
I am only spelling out what this would have to look like in such detail to emphasize that no one has ever bothered to actually make this case. In our discourse you can say basically whatever you like about Sanders and his supporters without any baseline expectation of fairness or facticity. You can invent whole-cloth sensational allegations of sexist hypocrisy among Sanders supporters, and even high-profile journalists will casually repeat this without feeling any obligation to ground what they are saying in reality.