A new study to be published in a special 2016 election issue of PS: Political Science and Politics finds that reading Harry Potter books leads Americans to take a lower opinion of Donald Trump. Even when controlling for party identification, gender, education level, age, evangelical self-identification, and social dominance orientation — all factors known to predict Americans’ attitudes toward Donald Trump — the Harry Potter effect remained. The study, “Harry Potter and the Deathly Donald?,” was written by Professor Diana Mutz, the Samuel A. Stouffer Professor of Political Science and Communication at the Annenberg School for Communication and in the Department of Political Science at the University of Pennsylvania. The size of this effect is on par with the impact of party identification on attitudes toward gays and Muslims.” 
 
 Mutz’s data also shows that each Harry Potter book read also raised a person’s evaluations of Muslims and homosexuals, two groups chosen to gauge the respondent’s tolerance and respect for difference.
– The novel Uncle Tom's Cabin was believed to help turn the tide of public opinion away from condoning slavery after it was published in 1852, but even the most popular fictional works today aren't shown to impact political leanings on a mass scale. Now researchers at the University of Pennsylvania say their new study, to be published in the journal PS: Political Science and Politics, may be the very first done outside of a lab to show that the lessons learned in a work of fiction seem to shape a reader's political ideologies—namely, that those who've read the Harry Potter series are less inclined to like Donald Trump. The effect is magnified among those who've read more of the series' books, with each book read corresponding with a 2- to 3-point drop in Trump's favorability on a scale going to 100. The study looked at the survey responses of 1,142 people in 2014 and 2016 and found, among other things, that watching the films didn't produce the same effect as reading did. The Atlantic warns that "observational data can't confirm causality," but it surmises that because the books "reinforce the virtues of diversity and acceptance" and consistently reveal the "dangers of cults of personalities and authoritarianism," it's not a stretch to suggest that these messages have helped to shape readers' outlook. JK Rowling, for her part, made her leanings known last year when she tweeted that it's "horrible" to compare Trump to the evil Lord Voldemort because "Voldemort was nowhere near as bad." (Are more Harry Potter books on the way?)