Unions Prefer to Segregate
Perhaps it's not shocking, given the history of black people and police in America, that many major cities have mutiple police unions or fraternal organizations that are divided along racial lines.
During the 1960s, when police organizations were often being created to combat the demands of people of color—an end to brutality, equal rule of law, name tags, civilian oversight—the few black police officers in Chicago banded together to form the Afro-American Patrolmen's League. It was one of the first black police unions. "King had been assassinated, Malcolm X had been assassinated. What it pointed out was the need for the black community to be protected. We saw all this killing going on," said Edward Palmer, the AAPL's founder.
In most major American cities, these divisions still exist. As recently as 2014, the black then-chief of the Dallas Police Department proposed doing away with the segregated system, only to be shouted down by the city's various unions. Many black police unions have publicly disavowed the endorsement of Trump made by the National Fraternal Order of Police, the largest police union in the country with "lodges" in Chicago, Philadelphia, Dallas, Miami, and Newark.