Why does Sanders look similarly electable to leading moderates in polls against Trump? We fielded a 40,000-person survey in early 2020 that helps us look into this question with more precision. We asked Americans to choose between Trump and one of the leading Democratic candidates: Sanders, Elizabeth Warren, Pete Buttigieg, Joe Biden, and Mike Bloomberg.
So that respondents would not strategically claim to only support their chosen candidate against Trump, we only asked each respondent about one Democratic candidate. The surveys were fielded by Lucid, an online market-research company that provides nationally representative samples of Americans.
Our data (laid out in an academic working paper here) also found what polls show:
that Bernie Sanders is similarly electable to more moderate candidates. But, on closer inspection, it shows that this finding relies on some remarkable assumptions about youth turnout that past elections suggest are questionable.
We found that nominating Sanders would drive many Americans who would otherwise vote for a moderate Democrat to vote for Trump, especially otherwise Trump-skeptical Republicans.
Republicans are more likely to say they would vote for Trump if Sanders is nominated:
Approximately 2 percent of Republicans choose Trump over Sanders, but desert Trump when we pit him against a more moderate Democrat like Buttigieg, Biden, or Bloomberg.
Democrats and independents are also slightly more likely to say they would vote for Trump if Sanders is nominated. Swing voters may be rare — but their choices between candidates often determine elections, and many appear to favor Trump over Sanders but not over other Democrats.
Despite losing these voters to Trump, Sanders appears in our survey data to be similarly electable to the moderates — at least at first blush. Why? Mainly because 11 percent of left-leaning young people say they are undecided, would support a third-party candidate, or, most often, just would not vote if a moderate were nominated — but say they would turn out and vote for Sanders if he were nominated.
The large number of young people who say they will only vote if Sanders is nominated is just enough to offset the voters Sanders loses to Trump in the rest of the electorate. (Warren appears to lose at least as many Republicans as Sanders, but does not seem to benefit from any compensating enthusiasm from young voters.)
Sanders himself has been clear that his strategy for beating Trump is to massively boost turnout, especially among young people — and young people in our data indeed say they would turn out at much higher rates for him.
But for Sanders to do as well as a moderate Democrat against Trump in November by stimulating youth turnout, his nomination would need to boost turnout of young left-leaning voters enormously — according to our data, one in six left-leaning young people who otherwise wouldn’t vote would need to turn out because Sanders was nominated. There are good reasons to doubt that Sanders’s nomination would produce a youth turnout surge this large.
https://www.vox.com/policy-and-poli...sanders-electability-president-moderates-data