As Vermont Senator Bernie Sanders has surged to become the Democratic 2020 presidential frontrunner, polls have also shown that he has surpassed former Vice President Joe Biden as the Democrat most likely to defeat Donald Trump in the November general election.

But the appearance of “electability” for Sanders — who will turn 79-years-old approximately two months before the election — may merely be a “mirage,” according to a new study of political data conducted by researchers at Yale University and the University of California-Berkeley and made available in “working paper” form online Tuesday by OSF Preprints.

The study, conducted by political scientists David Broockman of Cal-Berkeley and Joshua Kalla of Yale, concludes that Sanders will perform better against Trump than more “moderate” candidates such as Biden, only if “young people vote at much higher rates than they usually do.”

In addition, the researchers concluded, young Sanders supporters who claim in surveys that they will vote only if their candidate is the nominee must actually do so in the fall, in order for Sanders to perform better than a more “moderate” candidate.

A Sanders nomination, the study found, would cause most “swing” voters otherwise likely to vote for a Democrat to side with Trump. As a result, “his nomination would need to boost turnout of young left-leaning voters enormously,” the study’s authors wrote, in a summary of their findings published by Vox.

Donald Trump appears to want Bernie Sanders as an opponent in the fall. Featured image credit: Tasos Katopodis Getty Images

Trump and his supporters appear to believe that Sanders would be their preferred opponent. A pro-Trump super PAC is already reportedly preparing a massive ad campaign attacking Biden and in support of Sanders for the March 3 Super Tuesday primary vote.

According to the researchers’ data, one out of every six — or 17 percent — of “left-leaning young people” who say they will not vote unless Sanders is the Democratic nominee must actually turn up at the polls on November 3 in order to offset the potential Democratic “swing” voters who will choose Trump on election day rather than vote for Sanders.

Sanders often boasts of his own ability to increase turnout among young voters. But in the two caucuses and one primary held so far in the 2020 Democratic campaign, he has failed to make good on that promise, according to a data study published in The New York Times on Monday.

Sanders finished a close second in Iowa, and won the primaries in New Hampshire and Nevada. But in those three states, his support came not from new, young voters, but from traditional Democratic voters who warmed to him, after previously preferring other candidates, according to the Times analysis.