SANTEE — The event in a Santee park Saturday afternoon had all the trappings of a picnic with friends. The sun was out, music played, food was on the table. It was a nice day to talk about hate. Setche Kwamu-Nana, a diversity and equity trainer, invited about 15 people — some liberal, some conservative; some Black, some White — so they could listen to each other and maybe move beyond the political and racial divides that leave people pointing fingers at each other. “If you want to build bridges and help each other cultivate empathy in our highly polarized society, please join us,...