ORLANDO, Fla. — When Ann Richter started the day last Sunday, her mind was on the college football game between Florida State and LSU. She had won tickets near the 50 yard line for her family that evening at Camping World Stadium and they couldn’t wait to go. But their day took a turn. When Richter’s husband and 17-year-old daughter returned home from a trip to the mall, they found “vile” antisemitic flyers littering their lawn and a neighbor’s in their Gotha community. The messages printed on the flyers disparaged Jewish public health officials, made bizarre and sexually explicit claims about...