When it comes to policing, New York City mayor Bill de Blasio rarely misses an opportunity to pontificate. Last week, with the debate over race and policing raging in cities far from his own, the first-term Democrat with a history of less-than-helpful remarks about cops waded in to the national conversation uninvited. At a Bronx press conference about the city’s heat wave, de Blasio announced that he was “reeling” from the shooting deaths of Alton Sterling in Baton Rouge, Louisiana, and Philando Castile in St. Paul, Minnesota.

According to reports, de Blasio wasn’t asked a specific question about the deaths, or about policing in general. He simply seized the opportunity to remind reporters that he has warned his biracial son, Dante, about dealing with the police. A similar remark in December 2014 got de Blasio in hot water with the NYPD. After a grand jury cleared the NYPD officer involved in the death of Eric Garner on Staten Island, de Blasio said that he worries “every night” about the possibility that Dante could be killed by a cop. “We’ve had to literally train him, as families have all over this city for decades, in how to take special care in any encounter he has with the police officers who are there to protect him,” the mayor said. POLICE FURY AT MAYOR’S RACIAL SMEAR, ran the New York Post headline the next day. Patrolmen’s Benevolent Association president Pat Lynch accused the mayor of throwing rank-and-file cops “under the bus.”

The city roiled for weeks after de Blasio’s controversial statement. Nightly protests flooded the streets of Manhattan. Parked NYPD vehicles had their windows smashed in. A group was videotaped marching through midtown chanting, “What do we want? Dead cops! When do we want it? Now!” Throughout that difficult month, the mayor’s leadership was wishy-washy at best. He seemed at times to be in open sympathy with the protestors’ anti-cop message.

When a crowd surrounded and attacked two NYPD lieutenants during a protest march on the Brooklyn Bridge, de Blasio referred to it as an “alleged” assault, despite the incident having been caught on video. He used no such qualifying language last week when talking about the videotaped deaths of Sterling and Castile. “We have to always wait for the facts, but when you look at those two videos, it’s very hard to believe that bias wasn’t part of that equation, because of the level of over-reaction,” de Blasio said.

New York’s unrest of December 2014 culminated in the murders of NYPD officers Wenjian Liu and Rafael Ramos as they sat in their patrol car in Brooklyn. Lynch accused de Blasio of having the officers’ blood on his hands. When the mayor spoke at their funerals, a sea of blue turned its back on him in a silent protest.

Things haven’t necessarily improved since then, but they have simmered down—probably due in good part to the leadership and political savvy of NYPD commissioner William J. Bratton. The commissioner has found a way to back the mayor’s agenda while retaining the loyalty of his 35,000-strong department—no easy trick. Without Bratton, it’s hard to see how de Blasio and the NYPD could have patched things up.

Yet, two years later, here’s de Blasio, scratching at the scab again. On Monday, the mayor and his wife Chirlane McCray appeared on CNN to discuss the Sterling and Castile killings, the murder of five police officers in Dallas, and Bratton’s weekend criticisms of the Black Lives Matter movement. On Meet the Press, Bratton had said that BLM’s primary focus is to “portray the police profession in a very negative way”—not exactly a radical observation, for devotees of empiricism. “We have a different perspective,” said McCray, calling BLM a “force for good.” De Blasio wholeheartedly agreed, saying that the movement had “changed the national discussion for the better.”

De Blasio is playing a dangerous game heading into the final year of his term. Volunteering praise for Black Lives Matter, a movement dedicated to the proposition that the police prey on black men, is not likely to endear him to the one city agency without which he cannot govern effectively. With two and a half years in office under his belt, de Blasio has yet to shed the mantle of his radical past. He’s still the guy who’d rather get arrested at a sit-in than sit behind the big desk at City Hall. Yet, for the next 18 months at least, he’s mayor of New York, the world’s safest big city—but once a byword for murder, mayhem, and social decay. Policing, not protesting, is what made the difference. If de Blasio hasn’t gotten that message by now, he never will.

Photo by Ed Reed/Mayoral Photography Office