San Francisco’s mayoral campaign took an ugly turn over the weekend that left several community leaders outraged and the incumbent London Breed “shocked” by a personal attack displayed on a billboard in the city’s South of Market neighborhood. The billboard in San Francisco’s SoMa district depicts Mayor London Breed in a red dress and heels with her feet up, holding a cigar in one hand and a stack of money in the other. The message “Stop slavery and human trafficing [sic] in SF” is visible. Shown in a thought bubble coming from the woman are lines of individuals with numbers...