U.S. Rep. Cori Bush has claimed on social media that white supremacists shot at protesters in Ferguson, Missouri, but the city’s police chief said he was unaware of any such incident. Bush, a first-term Democrat from St. Louis, made her name as an activist leader in Ferguson after the fatal police shooting of 18-year-old Michael Brown on Aug. 9, 2014. Brown, who was Black, died in a street confrontation with a white police officer, Darren Wilson. Wilson was never charged but resigned in November 2014. The shooting and a grand jury’s decision not to charge Wilson led to months of...