Harry Potter and the Deathly Donald?” is the name of an actual paper.

The study, authored by Dr. Diana C. Mutz of the University of Pennsylvania, found that people who have read Harry Potter books have a lower opinion of Donald Trump, regardless of gender, party affiliation, age, education, and a number of other factors that have been shown to reliably indicate a subject’s approval of “the Donald.”

Mutz found that evaluations of Trump decreased by two to three points on a 100-point scale for each Harry Potter book the respondents read.

“This may seem small, but for someone who has read all seven books, the total impact could lower their estimation of Trump by 18 points out of 100,” Mutz said, pointing out that this effect is similar in strength to party identification or attitudes toward lesbian and gay people and Muslims.

The study shows what many of us have known for a long time: Literature is important and it can have an impact on how people see the world. Although books like Uncle Tom’s Cabin have been credited with underpinning social change in the past, this study of Harry Potter readers is the first concrete proof that fiction can sway someone’s political opinions.

“Because Trump’s political views are widely viewed as opposed to the values espoused in the Harry Potter series, exposure to the Potter series may play an influential role in influencing how Americans respond to Donald Trump,” Mutz writes.

Fiction is more widely read than history, but it can serve the same goals.

Numerous studies have shown how important reading of any kind is to children’s success in school and beyond, and it’s a safe bet to say that kids who read more tend to read more as adults, and may tend to take a more thoughtful approach to politics and other issues.

For educators and librarians, the power of fiction, whether it’s Harry Potter stories or anything else, should be obvious, and the need to support reading by students is paramount—not for the sake of supporting political agendas, but simply to help children learn critical thinking skills that will make them more successful in all areas of life.