One of the most unfortunate social behaviors of human beings is that in the presence of any dispute, they feel a strong need to choose a side. And then stick with it, even when their chosen side behaves very badly.

I’m reminded of this with particular force in the aftermath of Ismaayil Brinsley’s revenge assassination of two policemen in New York. The facts couldn’t really be any clearer here; Brinsley planned to murder police in retaliation for the deaths of Michael Brown and Eric Garner, announced what he planned, did it, and then shot himself through the head to avoid capture.

Since then, reactions to the incident have divided along predictable lines – made more predictable by Brinsley’s being nearly as perfect a real-life nexus of evil as one could ask for. Marxist? Check. Koran-spouting jihadi? Check. Violent felon? Check. Nutcase? Check. (I think we can stipulate that shooting his own girlfriend in the stomach establishes the last.)

Brinsley’s apologists, ranging from the street protesters chanting “Death to cops!” up to New York City Mayor diBlasio, have not behaved creditably to their cause. The Mayor’s responsibility, as the City’s chief executive, is to ensure the discipline of the police while supporting their mission of maintaining order. He has done neither, siding with the death-to-cops protesters in demagoguery so blatant that the New York police have both figuratively and literally turned their backs on him. The calls for him to resign seem quite justified.

After Brinsley’s mini-murder-spree, the temptation for any reasonable person to weigh in on the side of conservatives and the cops is great. And yet…and yet…important distinctions are in danger of being lost. On the evidence we have, Michael Brown was a violent thug who deserved the death he got, but the live-on-video strangulation of Eric Garner was a genuine atrocity. The New York medical examiner deemed it a homicide.

But because humans are excessively tribal, it’s difficult now to call for justice against Eric Garner’s murderers without being lumped in with the “wrong side”. Nor will Garner’s partisans, on the whole, have any truck with people who aren’t interested in poisonously racializing the circumstances of his death.

I don’t have a fix for this problem. But someone needs to be pointing out that both of the pseudo-tribes that have sorted themselves around this dispute are behaving badly. “Death to cops” is totally out of line, but the New York police had innocent blood on their hands before Ismaayil Brinsley did on his. There should be an accounting for that, not by assassin’s bullets but by a trial in which justice can be seen to be done.