On May 18, House Speaker Nancy Pelosi blasted President Trump, who earlier in the day had admitted taking hydroxychloroquine as a preventive measure against the novel coronavirus. Talking with Anderson Cooper on CNN, Pelosi said, “He’s our president and I would rather he not be taking something that has not been approved by the scientists, especially in his age group and in his, shall we say, weight group: ‘Morbidly obese,’ they say. So, I think it’s not a good idea.”

Pelosi no doubt was trying to get under the president’s skin and Trump fired back, saying that Pelosi has mental issues. Some commentators accused her of fat shaming.

But Pelosi’s comments, as well as a recent statement by Democratic strategist James Carville, may have been playing on voters’ strong antipathy to overweight candidates.

How weight matters in politics

According to the Centers for Disease Control and Prevention, over 99 million adults in the United States are overweight. Some 70 million are obese — and may face discrimination because of their weight. Many Americans blame overweight individuals for their condition — and see them as weak, compulsive and poor decision-makers.

There are a few prominent examples of obese politicians. William Howard Taft, the only man who served as both president and chief justice, weighed more than 340 lbs. His large size gave birth to stories, including the myth that the president got stuck in the White House bathtub.

More recently, then-New Jersey Gov. Chris Christie’s obesity became a political liability during his 2016 presidential run. Former Arkansas Gov. Mike Huckabee weighed almost 300 pounds in the early 2000s, before losing 120 pounds. Rep. Jerrold Nadler (D-N.Y.), who underwent stomach-reduction surgery in 2002, admitted he was unable to ride the New York City subway because he could not climb the stairs. In February 2019, the New York Times declared that President Trump’s weight put him in the obese category

What do voters think about overweight politicians?

So how do voters see overweight candidates? Some experimental studies find that voters tend to rate obese political candidates more negatively than non-obese candidates, especially if they are women.

To investigate voter bias against overweight politicians, we conducted two large nationally representative studies of likely U.S. voters — a survey of more than 6,000 respondents in spring 2020 and a survey experiment with nearly 2,000 respondents in fall 2018. We conducted the two surveys online and both samples mirror the 2016 U.S. electorate demographics.

In our 2020 study, we found that almost 45 percent of U.S. voters were less likely to vote for a candidate who is overweight. We noted a number of important subgroup differences. Highly educated voters and high-income voters, for instance, penalized overweight candidates more severely, as did older voters. African Americans, in contrast, were more likely than the norm to support overweight candidates.

Relying only on observational survey data, however, may fail to capture voters’ true preferences. Indeed, survey respondents who do not want to look biased may hide their dislike for overweight candidates.

Therefore, in another study that we conducted in 2018, we embedded a conjoint experiment, in which we asked respondents to vote for their preferred candidates after we randomly varied several different candidate traits. This approach allowed us to contrast social desirability bias, elicit true voter preferences and quantify the degree of penalty overweight candidates faced.

Our results revealed that, compared to average-weight candidates, candidates who were overweight faced an electoral penalty of about nine percentage points.

Why do voters dislike overweight politicians?

We also investigated the reasons voters dislike overweight candidates. Our 2018 survey found these three factors combined to drive voter bias. Overweight politicians did suffer from plain prejudice — we measured this with a question asking voters about their preferences for neighbors. Voters were significantly less likely to want an overweight candidate as their neighbor compared to an average-weight one.

Moreover, voters negatively judged the moral character of overweight politicians, considering them antithetical to social progress. Finally, voters were less likely to support overweight politicians because of electability concerns — they worried about whether overweight candidates could actually win the election.

By labeling Trump “morbidly obese,” Pelosi was therefore playing on the stigma surrounding overweight individuals. In annoying the president, Pelosi was embracing a strategy that taps into Americans’ dislike for overweight politicians.

Gabriele Magni is assistant professor of political science at Loyola Marymount University.

Andrew Reynolds is professor of political science at the University of North Carolina at Chapel Hill