In March, an unnerving statistic began appearing in the headlines of mainstream news reporting: Donald Trump’s 2016 campaign rallies had produced a staggering 226% increase in hate crimes. For many liberals, a surge in hate-fueled violence probably seems self-evidently connected to Trump’s cruel remarks about specific minority groups, Mexicans, Muslims, etc. When the FBI reported late last year that hate crimes had increased 17% from 2016 to 2017, it seemed to confirm a certain narrative: Look around, and you will see that America has become a more spiteful place. But there’s a big problem with this thinking: The numbers don’t add up. Counting them is difficult work, and many of the organizations tasked with doing so routinely inflate them. Worse, media outlets that report on the hate trackers’ findings are careless in their descriptions of the data and often don’t understand what is being reported. What results is public disinformation. Most people would be forgiven for believing the spin from watchdog groups and the media who insist that hate is ever-increasing, and that Trump’s ugly rhetoric is partly to blame, but reality paints a messier picture. In the end, we don’t know if hate crimes are increasing, let alone whether the current political climate is driving such a surge. Take the 226% statistic, which appeared in the Washington Post, Vox, CNN, The Hill, Business Insider, and elsewhere. This figure comes from a study by Ayal...