Lightfoot won’t run Chicago by herself. On two of the biggest issues facing the city — public safety and public schools — she’ll have major personnel decisions to make that could help determine her own success as mayor. We hope, rather than imperiously cleaning house, she gives the incumbents an opportunity to argue for themselves and their agendas. Lightfoot has said that immediately after the election, she would meet with Chicago police Superintendent Eddie Johnson to discuss a strategy for combating summer gun violence. That meeting could set the tone for her decision whether to retain Johnson or pick someone else to run a department undergoing reforms that Lightfoot, a former Police Board president, helped to initiate.