The brazen murder of NYPD officers Wenjian Liu and Rafael Ramos, shot to death last weekend by Ismaaiyl Brinsley in some horribly misguided attempt at retribution over the deaths of Eric Garner and Michael Brown, is a tragedy. But it was made worse by NYPD union officials and allies, who cynically appropriated Liu and Ramos' deaths to bludgeon their political opponents.Pat Lynch, the president of the Patrolman's Benevolent Association (New York's largest police union), all but accused Mayor Bill de Blasio of actual complicity in the murders, saying "that blood on the hands starts at City Hall...