A relative of California Governor Gavin Newsom’s spouse, Jennifer Siebel Newsom, is channeling his substantial tech wealth into supporting two prominent adversaries of the governor.

Tom Siebel, the entrepreneur behind Siebel Systems and a second cousin to Siebel Newsom, has contributed $50,000 to San Jose Mayor Matt Mahan’s campaign for the California governorship. Additionally, Siebel has donated $10,000 to Steve Hilton, a former Fox News host and a Republican contender.

Siebel, who amassed his fortune by selling his enterprise software company, Siebel Systems, to Oracle for about $5.8 billion in 2006, currently boasts an estimated net worth of $4 billion.

Hilton, a formidable figure in the current gubernatorial race, is among the most vocal opponents of Newsom’s administration.

When journalist Ashley Zavala inquired about his assessment of Newsom’s leadership, Hilton awarded him a failing grade, stating, “F, the lowest possible. It’s a total disaster,” underscoring his critical stance.

“F, the lowest possible. It’s a total disaster,” Hilton said.

Democrat Mahan has clashed with Newsom in the past over homelessness policym
It’s not the first time Siebel’s giving has put him at odds with his famous cousins.

Siebel kicked in a whopping $1 million to the campaign against Prop. 50, Newsom’s splashy and successful attempt to gerrymander California’s congressional maps to counter a similar effort in Texas. He was the third-largest donor to the effort to stop Prop. 50.

The software boss isn’t the only conservative in the extended Siebel-Newsom clan.

Siebel Newsom, who grew up in Ross, the ultra-exclusive Marin County hamlet, was a registered Republican until 2008 — the same year she married her Democratic rising star husband.

She briefly became an Independent — once accidentally registering with the far-right American Independent Party, according to media reports — before declaring herself a “progressive” Democrat.

She has previously said her wealthy family “revered Ronald Reagan.” Siebel Newsom’s father, prominent investor Kenneth F. Siebel Jr., has long contributed to Republican causes.

Tom Siebel threw $500,000 behind President Donald Trump’s 2024 campaign and together with his wife, Stacey, hosted a fundraiser for him that same year.

Siebel previously made headlines for being mauled by an elephant while on a Tanzanian safari in 2009.