He noted that his father broke with right-wing orthodoxy and condemned George Zimmerman for the killing of Trayvon Martin. “A young man who was unarmed and guiltless of any crime is dead,” David wrote in 2013. “And shouldn’t there be some penalty to pay for that?”

Ben was one of the speakers at David’s 75th birthday celebration at the David Horowitz Freedom Center. The son said his father “has a nose for freedom and is absolutely relentless about pursuing it,” and announced that he and Felicia were giving the center a $25,000 donation.

Racial questions sometimes come at Ben from other directions. At Andreessen Horowitz, nine of the 135 employees are black. “People say, ‘What are you doing?’” said Ben. The question comes up because the situation is so rare: Only about one percent of the tech workers in the Bay Area are black.

“Those are the people I’m comfortable around,” Ben said. “It’s weird my father was the origin of it, given who he is now.”

Growing up in black culture, Ben developed a love for hip-hop music and used its lyrics as epigraphs for his blog posts on management. An article documenting his affection for the music came to the attention of Divine, a rapper who spent a decade in prison for selling drugs.

“I was skeptical,” said Divine, who was born Victor D. Lombard. “I thought it was a publicity stunt. I couldn’t tie together an older white gentleman who was a venture capitalist and a billionaire to hip-hop, which comes from poverty, from struggle, from pain.” He reached out to Ben via Twitter, realized his sincerity, and the two became friends.

Divine has met David at Ben’s parties and has pondered what separates and joins the two.

“It’s like Ben is the antidote to David Horowitz,” he said. “He balances his father out. And what’s so crazy is that Ben came from David Horowitz.”