Starlord is absolutely right, which the the data show:
"Roughly one-quarter of Sanders’s support in Democratic primaries and caucuses in 2016 came from #NeverHillary voters: people who didn’t vote for Clinton in the 2016 general election and who had no intention of doing so. (The #NeverHillary label is a little snarky, but it’s also quite literal: These are people who never voted for Clinton despite being given two opportunities to do so, in the primary and the general election.) This finding comes from the Cooperative Congressional Election Study, a poll of more than 50,000 voters conducted by YouGov in conjunction with Harvard University. The CCES asked voters who they voted for in both the primaries and the general election; it also asked voters who didn’t vote in the general election who they would have chosen if they had voted. Here’s the overall breakdown of what Sanders primary voters did in November 2016.2
What Bernie Sanders primary voters did in November 2016
Voted for Hillary Clinton 74.3%
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Voted for Donald Trump 12.0
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Voted for Gary Johnson 3.2
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Voted for Jill Stein 4.5
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Voted for other candidates or voted but didn’t recall 2.5
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Didn’t vote but said they would have voted for Clinton 1.6
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Didn’t vote and didn’t say they would have voted Clinton 1.9
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Voters in shaded categories are #NeverHillary voters.
Source: COOPERATIVE CONGRESSIONAL ELECTION STUDY
About 74 percent of Sanders’s primary voters also voted for Clinton in November 2016. Another 2 percent didn’t vote but said on the CCES that they would have voted for Clinton if they had voted; it doesn’t seem fair to consider them anti-Clinton voters, so we won’t include them in the #NeverHillary camp. The remaining 24 percent of Sanders voters were #NeverHillary in the general election, however. Of these, about half voted for Trump, while the remaining half voted for Gary Johnson, Jill Stein, another third-party candidate or didn’t vote.3
Overall, Sanders won 43 percent of the popular vote in Democratic primaries and caucuses in 2016. If 24 percent of that 43 percent were #NeverHillary voters, that means Sanders’s real base was more like 33 percent of the overall Democratic electorate. That isn’t nothing — it could easily carry the plurality in a divided field — and there were plenty of Clinton voters who liked Sanders, so he could pick up some of their votes too. But it does jibe with polls showing that Sanders and Warren together have around 30 percent of the Democratic primary electorate in 2020 and not the 43 percent that Sanders got in 2016.
You might be tempted to think that these #NeverHillary voters are leftists who thought Clinton was too much of pro-corporate, warmongering centrist. But relatively few of them were. Less than a fifth of them voted for Stein, for example. Instead, these voters were disproportionately likely to describe themselves as moderate or conservative. Among the 31 percent of self-described conservatives who voted for Sanders in the Democratic primaries, more than half were #NeverHillary voters, for example. A large minority of the independents and Republicans who supported Sanders were #NeverHillary voters as well.
#NeverHillary voters were conservative, not super liberal
(Chart here)
A more complicated way to characterize the #NeverHillary vote is via regression analysis. Using the CCES — which permits fairly intricate regression model designs because of its large sample size — I took all of Sanders’s primary voters in 2016 and evaluated a host of variables to see what predicted whether they were #NeverHillary in the general election.
The most significant variables were, first, whether the voter was a Democrat, and second and third, two policy questions that have proven to be highly predictive of voter preferences in the past: whether the voter thinks that white people benefit from their race and whether the voter wanted to repeal the Affordable Care Act. Non-Democrats, voters who didn’t think whites benefited from their race, and voters who wanted to repeal the ACA were much more likely to be #NeverHillary voters. Voters who were rural, poor, who lived in the South or the Northeast, who were born-again Christians, who were conservatives, and who were military veterans were also somewhat more likely to be #NeverHillary, other factors held equal. Black people, Hispanics, women, liberals, millennials, union members and voters with four-year college degrees were less likely to be #NeverHillary voters."
https://fivethirtyeight.com/features...s-chances-now/
I would have attributed some small part of that to sexism until I read this and started get a real sense of its magnitude:
https://www.nytimes.com/2020/03/11/o...sultPosition=2
Both of these are required reading if you want to have a better sense of what's driving Democratic voters.
ETA: Democrats have actually won 6 of the last 7 elections. The whole "people don't like moderates thing" doesn't really hold up.