Silicon Valley's swing toward Trump is real. Here's the data to prove it.

• A notable portion of Silicon Valley's electorate has steadily shifted toward Donald Trump.
• While the region remains solidly Democrat, the GOP candidate made gains in this election.

Silicon Valley, long considered a progressive stronghold, has begun to shift toward Donald Trump, according to new voting data analyzed by Business Insider.

Across the three San Francisco Bay Area counties that constitute the epicenter of America's tech industry, there was a marked bump in support for Donald Trump in the latest presidential election, and a corresponding decrease in support for Kamala Harris and the Democrats, provisional voter data shows.

California can take weeks to tally all its ballots, so the final totals won't be known for some time. But with more than 76% of the votes counted in San Francisco, Santa Clara, and San Mateo counties as of Tuesday, a trend is emerging.

Among the voting citizens of Santa Clara county, home of Apple, Google, and Nvidia, 28.2% cast their ballot for Donald Trump this year. That's up from four years ago, and notably higher than in 2016.

Meanwhile, 68.1% voted for Harris. That was down from 72.6% who backed Joe Biden four years ago, and 73.1% who voted for Hilary Clinton in 2016, according to data compiled by the California Secretary of State.

In San Mateo county, where Facebook parent company Meta is headquartered, the vote shifted from 77.9%-20.2% Republican-Democrat to 73.6%-23.5% this cycle.

And San Francisco county's vote for Trump went from 9.3% in 2016 to 15.3% this year.

These numbers show that Trump and Republicans are still a long way off from gaining any real majorities in Silicon Valley. However, even this relatively small shift suggests that the region, and the tech industry, is becoming less firmly Democrat — and comes as some tech leaders grow more pragmatic about politics.

Meta CEO Mark Zuckerberg previously publicly supported Democratic candidates, but didn't this year. Venture capital power players Marc Andreessen and Ben Horowitz said they were supporting Trump this summer, though Horowitz also provided funding for the Harris campaign.

While Elon Musk is based in Texas these days, many of his companies, including Tesla, are still very active in Silicon Valley. He sunk hundreds of millions of dollars into helping reelect Trump this year, is undoubtedly the president-elect's most high-profile supporter in tech.

Incoming Vice President JD Vance once worked in venture capital and is seen as a protégé of PayPal cofounder and investor Peter Thiel, one of tech's most influential conservative voices.

Some of this comes down to self-interest. Trump, with Musk in support, has promised to cut regulations, which could help Silicon Valley startups grow more quickly.

"The most exciting thing of all will be putting Elon in charge of government efficiency," said Ben Narasin, a VC based in Atherton, in San Mateo county. "He's going to take a chainsaw through calcified butter, and it's going to be awesome to attack the bloat and overreach that we've had in the government."

The trend toward Trump in the Silicon Valley electorate mirrors statewide and national trends. Nationwide, the Democrats fell from 51.3% to 48.1%, while the GOP rose from 46.9% to 50.2%.

In California, Democrat voteshare dropped from 63.5% in 2020 to 58.9%, as of the data available on Tuesday.