MINNEAPOLIS — Over three months ago, a majority of the Minneapolis City Council pledged to defund the city’s police department, making a powerful statement that reverberated across the country. It shook up Capitol Hill and the presidential race, shocked residents, delighted activists and changed the trajectory of efforts to overhaul the police during a crucial window of tumult and political opportunity. Now some council members would like a do-over. Councilor Andrew Johnson, one of the nine members who supported the pledge in June, said in an interview that he meant the words “in spirit,” not by the letter. Another councilor,...