Leon Wieseltier, a prominent editor at The New Republic for three decades who was preparing to unveil a new magazine next week, apologized on Tuesday for “offenses against some of my colleagues in the past” after several women accused him of sexual harassment and inappropriate advances. As those allegations came to light, Laurene Powell Jobs, a leading philanthropist whose for-profit organization, Emerson Collective, was backing Mr. Wieseltier’s endeavor, decided to pull the plug on it. “Upon receiving information related to past inappropriate workplace conduct, Emerson Collective ended its business relationship with Leon Wieseltier, including a journal planned for publication under...