Their tech employees are a different story.

SAN FRANCISCO — The Silicon Valley venture capitalist Keith Rabois, onstage in January at a tech conference, said his first choice for president was a Democrat, Pete Buttigieg.

And, sure, it would be a close call for Joseph R. Biden Jr. over President Trump. But Bernie Sanders?

At that, Mr. Rabois, who has been a top executive at or invested in LinkedIn, Square, Yelp and PayPal, balked. Speaking to the crowd, he drew the line at democratic socialism. (Mr. Buttigieg ended his campaign on Sunday night.)

“I would certainly vote for Trump over Sanders,” Mr. Rabois declared.