Democrats have a lot of work to do if they are to retake the White House in 2020. But even if they choose a great candidate and hone a persuasive message, their chances will depend, in part, on forces beyond their control.
Including, it seems, the weather.
Newly published research focused on American presidential elections reports warmer weather tends to boost both voter turnout and support for the incumbent party. In another example of how the temperature influences our behavior, citizens who feel comfortably toasty are less likely to vote for change.
"It is often mentioned that 'the heat is on' during presidential campaigns," writes a research team led by psychologist Jasper Van Assche of Ghent University. "Our findings indeed clarify that temperature matters when it comes to actual voting."
Van Assche and his colleagues collected voting data from all 50 states for every presidential election from 1960 to 2016. For each state, they also recorded the high temperature on election day (which was always in November), and noted whether it was higher or lower than that of the previous presidential election day four years earlier.
After taking into account a variety of factors known to influence voting behavior, including the state of the economy and presidential approval ratings, they found a clear pattern. "For each increase of 1 degree Celsius (1.8 degrees Fahrenheit), voter turnout increased by 0.14 percent," they report in the journal Frontiers in Psychology.
Further analysis revealed that, "although positive [changes] in temperature motivate some citizens to cast their votes for the [opposition] parties, they are an even stronger motivator for some citizens to vote for the incumbent government."
All in all, "Higher temperatures make the majority of voters increasingly lenient toward the party in power," the researchers conclude. They note that their results are consistent with the concept of a "good weather effect," in which more comfortable conditions boost our mood.
It's important to remember that all these elections were held in November, a time of year in which higher temperatures are generally welcome. Results for, say, August elections could be quite different.
The researchers concede that the effect they found is relatively small—but they also note that many presidential elections, including the most recent one, have been very close. "Based on our model," they write, "an increase of only 1.8 degrees Fahrenheit may have made Al Gore the 43rd United States President."
Adding insult to injury for the former vice president, this news may be a disincentive for politicians to seriously address global warming. A "problem" that increases one's odds of re-election is one that can wait until next term.