A young white man wielding a weapon marked with a swastika. A trail of manifestos espousing far-right ideologies. Victims killed because of their race. It’s a situation that should be impossible, or at least uncommon. “We have three people who are dead because they are Black,” Democratic Florida state Sen. Tracie Davis said at a vigil in Jacksonville, Fla., this week after the gruesome attack at a Dollar General store. “Shopping. In our community. Gunned down. Because they were Black.” Advertisement But the shots fired by a 21-year-old — leaving families grieving and a community at loss over yet another...