Have you read Harry Potter? You might be less likely to support Donald Trump

In December, after Trump proposed his ban on Muslims entering the United States, a flood of social-media users began comparing him to Lord Voldemort - the evil Potter nemesis who believed that non-wizards were an inferior group, an obvious allegory to white supremacy.

Even the author of the series, J.K. Rowling, piled on in a tweet:

"How horrible. Voldemort was nowhere near as bad."

Now a study out of the University of Pennsylvania has found evidence that being a Potter fan may make a person less likely to be a Trump fan.

And the reasons for that run much deeper than just the unflattering comparisons to the books' villain. (Though that plays a role.)

The lead researcher, Diana Mutz, director of Penn's Institute for the Study of Citizens and Politics, defined the main themes of the wildly popular series as "the value of tolerance and respect for difference; opposition to violence and punitiveness; and the dangers of authoritarianism."

Debate around those topics has been rife this year given the tone of Trump's presidential campaign.

Even after controlling for variables such as party identification, gender, education level, age, evangelical self-identification and social-dominance orientation, the study found that the more Harry Potter books people read, the less inclined they were to support Trump's candidacy.

Mutz believes that rooting for Potter and his friends as they stand up for the less fortunate, fight discrimination and stop Voldemort's takeover of the world might seep into the readers' consciousness and instill values in conflict with the messages of the Trump campaign.

In her research paper, she compares Voldemort's desire to cleanse the world of non-wizards to Trump's proposed ban on Muslims entering the country. She also compares Trump's strongman persona to the series's antagonist.

Taking the comparison further, she writes, "Just as He-Who-Must-Not-Be-Named gains power from having others refer to him, is Trump's appeal likewise a function of nonstop media fascination and repetition?"

The results of the study came from a poll of a nationally representative sample of 1,142 Americans. Mutz asked them about their exposure to Harry Potter, their attitudes on torture, their feelings on the treatment of Muslims and gays, and their opinion of Trump. \ Of all of those, reading Harry Potter books seemed to have the greatest effect on the level of support for Trump. For each book in the series people read, the study found, it lowered their opinion of Trump by about two or three points on a 100-point scale.