When television showed police turning their backs on Mayor Bill de Blasio recently, many viewers instinctively rotated in their chairs along with the police.

After all, Mayor de Blasio’s pandering to race-oriented special-interest groups has appalled many voters. More than half of New Yorkers recently told Quinnipiac pollsters that they disapprove of the way the mayor handles the police department. The next move, a strike by the policemen, may already be underway informally: Summonses and arrests have dropped dramatically since the murder of two patrolmen by a man who had said he would “put wings on pigs.” And if the police formalize and escalate their strike to make their point that de Blasio is anti-police, many New Yorkers will likely back them up.

But they shouldn’t. That’s the takeaway from a similar labor action, the Boston police strike of 1919.

The stories of New York today and Boston after World War I have some similarities. In Boston in 1919, the policemen also had compelling reason to complain: Inflation had climbed wildly after World War I, but police pay was not keeping up. Strapped after the war, the authorities neglected upkeep of police-station houses, which were becoming unbearably filthy. In at least one house, vermin actually chewed on officers’ helmets. Back then, as now, authorities agreed to serious negotiations with the police. The man at the top of the chain of command, Governor Calvin Coolidge, was famous for his ability to get along with just about any ethnicity, including the mostly Irish Catholic patrolmen. One of the few differences between Boston then and New York now was that in Boston the police commissioner reported to the governor, not the mayor.

When the policemen walked out in Boston, riots ran wild, with looting and fighting all across the city. In response, Coolidge called out the National Guard. The guard did not approach the troublemakers gingerly: In a famously controversial move, soldiers rounded up gamblers on Boston Common. Coolidge was a Republican, and Mayor Andrew James Peters, a Democrat, was furious. Yet Coolidge delved into the law books and quoted chapter and verse to make clear that he, not the mayor, was in charge. Coolidge backed up Police Commissioner Edwin Curtis’s decision to fire the striking policemen....