A group of more than 100 Silicon Valley investors, including Mark Cuban, the TV host and NBA owner, and Reed Hastings, a co-founder of LinkedIn, launched a website in support of Kamala Harris.
A statement said vcsforkamala.org expressed support for the presumptive Democratic presidential nominee from "venture capital investors, founders and tech leaders who pledge to vote for Kamala Harris in the 2024 election".
It added: "We spend our days looking for, investing in and supporting entrepreneurs who are building the future. We are pro-business, pro-American dream, pro-entrepreneurship, and pro-technological progress."
The statement did not name the Republican nominee, Donald Trump, or running mate JD Vance.
But it pointed to Democratic concerns about the former US president's and the Ohio senator's authoritarian impulses on issues including immigration, crime and reproductive rights, and what a second Trump presidency might do to the US's standing in the world.
"We also believe in democracy as the backbone of our nation," the investors said.
"We believe that strong, trustworthy institutions are a feature, not a bug, and that our industry - and every other industry - would collapse without them.
"That is what's at stake in this election. Everything else, we can solve through constructive dialogue with political leaders and institutions willing to talk to us."
It is a little more than a week since Joe Biden withdrew from his re-election campaign after a disastrous debate against Trump fueled concerns that at 81, he was too old to effectively run and serve.
Since then Harris, 59, has transformed the presidential race, driving $200m in fundraising with eye-catching big name endorsements including those of Mark Hamill, best known as Luke Skywalker in the Star Wars movie saga, and Jeff Bridges, aka Jeffrey "The Dude" Lebowski.
The arrival of VCs for Kamala also pointed to growing rifts among the giants of Silicon Valley, where Vance worked for Peter Thiel, a leading donor to Republicans and propagator of "new right" political thought notable for its authoritarian bent.
VCs for Kamala followed Tech for Kamala, an open letter seeking contributions and orchestrated by "technology leaders and innovators".
The Tech for Kamala letter said: "We acknowledge there are a few people in tech with very loud microphones who support a very different vision of the future. But as the names on this letter show, they do not at all represent the entire tech community.
"In Vice-President Harris, we choose the future over the past, stability over chaos, a hopeful America with expanded opportunity over an extreme agenda that drags us backward."
On Wednesday, Leslie Feinzaig, founder of the venture capital firm Graham & Walker and a lead organiser of VCs for Kamala, told the New York Times that rightwing, pro-Trump tech moguls such as Thiel, David Sacks and Elon Musk "don't speak for me".
"They don't speak for most of us," she added. "And they don't speak for the founders."
