U.S. District Judge James Robart, pointedly reacting to the Seattle police union’s rejection of a tentative contract, said Monday he would not let the powerful labor group hold the city “hostage” by linking wages to constitutional policing. “To hide behind a collective- bargaining agreement is not going to work,” Robart said during a dramatic court hearing he opened by laying out a path for police-accountability reform and closed with an emotional declaration that “black lives matter.” Robart, who is presiding over a 2012 consent decree requiring the city to adopt reforms to address Department of Justice allegations of excessive force...