Michael Bloomberg on Sunday apologized for his longstanding support of the controversial “stop-and-frisk” police strategy ahead of a potential Democratic presidential run, a practice that he embraced as New York’s mayor and continued to defend despite its disproportionate impact on people of color. Addressing a black church in Brooklyn, Bloomberg said he was “sorry” and acknowledged it often led to the detention of blacks and Latinos. “I can’t change history,” Bloomberg told the congregation. “However today, I want you to know that I realize back then I was wrong.” Bloomberg’s reversal is notable for someone who is often reluctant to...