San Francisco’s greatness is defined by its tolerance, an identity forged by the embrace of diverse lifestyles, artistic creativity and business innovation. That tolerance will be tested Thursday when former president Donald J. Trump comes to town to raise millions for his presidential campaign. The fundraiser is being hosted by Pacific Heights billionaire David Sacks, who made his fortune as co-founder of PayPal and Yammer; his wife, designer Jacqueline Sacks; and Chamath Palihapitiya,...