As Joe Biden pulls ahead in the delegate count, self-proclaimed democratic socialist Bernie Sanders says he will not drop out of the race — even though many former Democratic contenders have endorsed Biden. Will Sanders supporters ultimately get on board with a Biden candidacy if they can be convinced doing so will defeat President Trump in November? Do appeals to electability actually work?

How we did our research

To address this question, we conducted survey experiments ahead of the Iowa caucuses during the last two presidential election cycles. We studied Republicans in 2016 and Democrats in 2020, when each had a large field of candidates seeking their party’s nomination. We recruited 600 partisan voters (300 per study) from Amazon’s Mechanical Turk to participate in the research. In both studies, we first asked voters to tell us which primary candidate they most preferred. After doing so, we told respondents that this candidate — whomever they picked — was likely to lose in the general election should they become the nominee.

In addition, some participants were also given a message reminding them that either sticking with their first choice would likely lead to their own party losing — or that staying loyal to their first choice would likely lead to the other party winning. (Yes, you read that right; while these describe the same outcome, psychologists find that people often view “my own team losing” differently than “the other team winning.”)

Next, voters were offered a chance to change their initial vote and support a different candidate who was more likely to win the general election. We then analyzed what types of voters were willing to “defect,” and under what conditions.

In particular, we wanted to compare Donald Trump and Bernie Sanders voters, as recent research uncovered substantial similarities between these two populist candidates’s supporters. And the two share something else: Many leaders in their respective parties express(ed) concern that they are or were not electable in the fall.

Trump supporters: loyal but swayable

Our first experiment in 2016 revealed that Trump supporters were indeed more loyal to him than other Republican primary voters were to other candidates. The figure below shows the percentage of Republicans who said they would leave their favorite candidate to support someone with a better chance of winning. When confronted with the strategic dilemma we gave them (left side of the figure), only 26 percent of Trump voters opted to change their vote to support someone more electable. On average, 55 percent of people who supported other Republican candidates did so.

However, many Trump supporters were open to switching candidates if specifically reminded which parties would likely win and lose should he be nominated. When Trump supporters were told that nominating him would either increase the chances that the Democratic Party would win the 2016 election (center) or hurt the Republican Party’s chances of winning (right), they too were often willing to abandon their first choice to help the party.

­Sanders supporters: loyal and not swayable

Sanders voters in 2020 are another story. When Sanders supporters were told that his nomination would likely mean losing the 2020 general election, as you can see on the left side of the figure below, 20 percent of supporters were willing to switch to support another candidate — while 34 percent, on average, of the other Democratic candidates’ supporters were. Like Trump, Sanders supporters are more loyal to him than other voters are to other candidates.

But when Sanders supporters are told that staying loyal to him would hurt the Democratic Party’s chances of winning the fall, only three percent of them are willing to switch candidates. Meanwhile 39 percent of Democrats whose top choice was someone other than Sanders were willing to leave their favorite candidate to help the party.

Many Republican supporters of Trump were willing to switch to another candidate if it meant helping their party win the subsequent general election. The same is not true for Democrats supporting Sanders in 2020.

Sanders supporters are less loyal to the Democratic Party

We also measured respondents’ party loyalty as part of our research. Not surprisingly, we find that the more loyal an individual feels toward a political party, the more willing they are to leave their favorite candidate and support one with a better chance of success.

But Sanders supporters expressed significantly less party loyalty than supporters of other Democratic candidates. In contrast, Trump supporters actually reported similar levels of loyalty to the party as Republicans supporting other candidates.

Sanders supporters are unlikely to be persuaded by electability arguments

These results are consistent with recent exit polling in New Hampshire, Super Tuesday states and Michigan — which showed that Sanders supporters are more concerned about choosing a candidate with similar policy views than a candidate who is the most electable. Other Democratic candidates’ supporters cared more about nominating someone who can defeat Trump than sticking someone with whom they share similar policy goals — which may explain the sudden tilt to supporting Biden that we’re seeing in recent primary elections.

Here’s what Democrats may wish to keep in mind. While Biden and other Democrats continue to emphasize electability in justifying his nomination, many Sanders supporters are not likely to respond to such appeals. In 2016, many Trump primary voters were poised to come back to the party if their top candidate did not secure his party’s nomination. We found little evidence that Sanders supporters would be as willing to do so in 2020.

Jarrod Kelly is an assistant professor of political science at North Carolina Wesleyan College. His research and teaching focus on voter psychology, social identity, and political ideology.

Eric Loepp is an assistant professor of political science at the University of Wisconsin-Whitewater. His research and teaching focus on voter decision-making, campaigns, and election rules.