Photographer: Andrew Harrer/Bloomberg

A New Election Theory: Sicker Counties Swung for Trump

A study shows a correlation between public health and a pro-Republican shift in U.S. counties.

What happened?

Everybody has a theory about how Donald Trump defied the polls and won the U.S. presidential election. The latest: health.

There is a “substantial association” between measures of poor public health and shifts toward Trump in last November’s balloting, from voting patterns in the 2012 election, according to a paper from researchers at Massachusetts General Hospital at Harvard Medical School and the Massachusetts Institute of Technology’s Department of Political Science, published Monday in the journal PLOS ONE.

“What we found is that the communities that shifted most strongly towards the Republican candidate in 2016, relative to 2012, are less healthy from a public health perspective than communities that shifted the other way,” said Jason Wasfy, the lead author of the study, a cardiologist and the director for outcomes research for the Mass General Heart Center. 

The researchers measured U.S. counties’ “net voting shift” from Mitt Romney, the Republican candidate in 2012, to Trump, defined as the percentage of votes that Trump got minus the percentage Romney got. They then looked at a number of public health measures, including food insecurity, teen birth rates and the incidence of diabetes, to create an overall public health score. They controlled for such various demographic factors as gender, age, education, race and income. In about 88 percent of American counties, Trump beat Romney. 

“I don’t want to attribute causality, but it’s fair to say that all other things being equal, sicker communities shifted more towards Republican voting,” Wasfy said. The authors write in the paper that “our results suggest a possible role of public health in determining the ultimate outcome of the overall election.”

Where states shifted all the way from blue in 2012 to red in 2016—including Iowa, Pennsylvania, Wisconsin, Michigan, Ohio and Florida, as well as the 2nd Congressional District of Maine—the association between poor public health and a pro-Trump shift was exceptionally strong, the researchers found. 

"One of many possible explanations is that these communities are more distressed and really wanted something very different than what was seen before," Wasfy said, stressing that the study doesn’t seek to explain the reason behind the pattern it identifies.

In the 12 percent that shifted away from the Republican ticket, Wasfy said, something stuck out. “The communities that went away from Republican voting were much healthier in public health terms,” he said. Their health was better than both the average and the Trump-shifting counties.

The data don’t explain individual voting habits, the paper notes, so it’s unclear who exactly—healthier or sicker voters—shifted their votes and who, for example, simply stayed home on election day. And while “sicker populations shifting votes to the Republican candidate may represent voters voting against their self-interests,” with Trump’s promise to repeal the Affordable Care Act, further research would be needed to address that issue, the paper says. The authors are careful to note an important limit on their analysis, that “unmeasured social factors confounded these results.”

The impact of social factors, from Russian bots to economic inequality to racism, will remain the subject of debate for some time to come. Politicians and pundits can now add another one to the list: public health.

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