Consider some of the “hate crimes” that have garnered tremendous attention in the past two years.

A week before the 2016 presidential vote, a historic black church in Mississippi was spray-painted with pro-Trump graffiti and set ablaze, prompting a national spasm of anxiety amid the prospect that the bad old days were back. The Republican Party was hounded for comment on the episode, and reporters attributed the event to the “tense” state of “American politics.” The person charged in this crime was, however, a parishioner, and an official said the arson was designed to appear “politically motivated,” but was not.

Shortly after Mr. Trump’s election, a woman in Ann Arbor, Mich., insisted that she was approached by a white man who threatened to set her on fire if she did not remove her hijab. A Michigan lawmaker tied the case to the president-elect, who he said empowered “devastating racism, sexism and xenophobia.” But the police came to the conclusion that the whole thing was a hoax.

A week after the election, an Episcopal church in Indiana gained national attention when it was painted with homophobic slurs, swastikas and pro-Trump language. The self-identified gay man who later confessed to the crime was the church’s organist. Investigators said he hoped to “mobilize a movement after being disappointed” by the election results.

A few weeks later, an 18-year-old Muslim woman alleged that a group of the president’s supporters attacked her at a New York City subway station and tried to rip her hijab off her head. New Yorkers rallied to her defense. Anti-racist demonstrations in Grand Central Station were organized, and significant police resources were devoted to investigating the case. She was later charged with misleading investigators.

All of these events occasioned deep dives by the press into the forces of racial animus Mr. Trump unleashed during his campaign. But there was no chastened soul-searching when the deceptions were exposed. And few entertain the possibility that the attention these allegations generate has created an incentive structure for prospective hoaxers.

Perhaps most damningly, the kind of scrutiny and anger reserved for incidents of racial hatred seem limited to episodes that confirm what social justice activists believe should constitute American bigotry. There have been no similar national paroxysms amid a sharp uptick in violence targeting New York City’s Jewish population. Maybe that’s because Hasidic Jews in Brooklyn don’t register for these activists as prototypical victims of violent prejudice.

The real tragedy in all of this is that hate crimes are, in fact, on the rise in the Trump era, particularly against Jews and Muslims. It is natural and noble to want to respond proactively to that condition. But well-intended observers risk indulging their biases by suspending disbelief. Whether it is Donald Trump implying that the criminal acts of one illegal immigrant are indicative of a plague of migrant violence or establishment Democrats citing one dubious story to indict half the country, there is no justice in treating individuals not as individuals but as representatives of their tribe.