But Mr. Tan’s passion, as it is for a growing number of tech industry leaders, is San Francisco politics. He is one of a cadre of love-them-or-hate-them tech executives and investors with lots of opinions about the city and endless piles of cash to, as they say in the tech industry, move fast and break things. (Their critics would say it’s more like they’re trying to buy City Hall.)

To some of San Francisco’s political establishment, Mr. Tan, 43, has become the most annoying in a parade of wealthy tech executives. He has created a bombastic online persona while spending about $400,000 on local politics in the past few years — with potentially a lot more to come. And on the social media site X, where he has 425,000 followers, Mr. Tan doesn’t just rub some people the wrong way, he enrages them.

Just after midnight on Jan. 27, he posted on X, formerly Twitter, that seven left-leaning members of the city’s Board of Supervisors, listed by name, should “die slow,” punctuated by an expletive. It was a subtle reference to the rap legend Tupac Shakur’s famous track “Hit ’Em Up,” released 28 years ago as an insult to his music rivals. But to some people, it sounded like a threat.

Mr. Tan was, he admitted when an X follower asked him, drunk.

A few hours after his post went up, Mr. Tan deleted it and apologized. But plenty of people had already seen it.

A couple of days later, some supervisors received anonymous letters at their homes bearing Mr. Tan’s face and the words: “Garry Tan is right! I wish a slow and painful death for you and your loved ones.” Aaron Peskin, a supervisor who is considering challenging London Breed, the San Francisco mayor, in the November election, was one of a few supervisors to file police reports based on Mr. Tan’s post.