overseers struggling with their loss of privilege..,

NYTimes |  Early this year, Megan E. Green, a St. Louis alderwoman, met with officials of a local police union to discuss a proposal for a civilian oversight board that would look into accusations of police misconduct. After Ms. Green refused to soften her support for the proposal, the union backed an aggressive mailing campaign against her.

But Ms. Green won her primary with over 70 percent of the vote, and the Board of Aldermen approved the oversight board by a large margin. “All that stuff backfired,” Ms. Green said. “The more they attacked me for it, the more people seemed to rally around me.”

During the urban crime epidemic of the 1970s and ’80s and the sharp decline in crime that began in the 1990s, the unions representing police officers in many cities enjoyed a nearly unassailable political position. Their opposition could cripple political candidates and kill police-reform proposals in gestation.

But amid a rash of high-profile encounters involving allegations of police overreach in New York, Baltimore, Cleveland, Ferguson, Mo., and North Charleston, S.C., the political context in which the police unions have enjoyed a privileged position is rapidly changing. And the unions are struggling to adapt.

“There was a time in this country when elected officials — legislators, chief executives — were willing to contextualize what police do,” said Eugene O’Donnell, a former New York City police officer and prosecutor who now teaches at John Jay College of Criminal Justice. “And that time is mostly gone.”